UnityでCanvasのButtonのTransformを変数として利用したい

前提・実現したいこと

UIのButtonのOnclick()メソッドが実行されたら、OnClickGetSprite()メソッドで、
クリックしたButtonのtransform をEmojiAに代入したいです。
” Object of type 'UnityEngine.Object' cannot be converted to type 'UnityEngine.UI.Button'”
というエラーになりました。解決方法についてご教示いただけますと幸いです。

発生している問題・エラーメッセージ

エラーが何行目か記載してほしいとのご依頼があったのですが、エラー文をみても記載がありません。
おそらく、public void OnClickGetSprite(Button button)の部分かな？と思っています。エラーの全文をコピペで貼っておきます。

 Object of type 'UnityEngine.Object' cannot be converted to type 'UnityEngine.UI.Button

<全文>
ArgumentException: Object of type 'UnityEngine.Object' cannot be converted to type 'UnityEngine.UI.Button'.
System.RuntimeType.CheckValue (System.Object value, System.Reflection.Binder binder, System.Globalization.CultureInfo culture, System.Reflection.BindingFlags invokeAttr) (at <fb001e01371b4adca20013e0ac763896>:0)
System.Reflection.MonoMethod.ConvertValues (System.Reflection.Binder binder, System.Object[] args, System.Reflection.ParameterInfo[] pinfo, System.Globalization.CultureInfo culture, System.Reflection.BindingFlags invokeAttr) (at <fb001e01371b4adca20013e0ac763896>:0)
System.Reflection.MonoCMethod.DoInvoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <fb001e01371b4adca20013e0ac763896>:0)
System.Reflection.MonoCMethod.Invoke (System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <fb001e01371b4adca20013e0ac763896>:0)
System.Reflection.ConstructorInfo.Invoke (System.Object[] parameters) (at <fb001e01371b4adca20013e0ac763896>:0)
UnityEngine.Events.PersistentCall.GetObjectCall (UnityEngine.Object target, System.Reflection.MethodInfo method, UnityEngine.Events.ArgumentCache arguments) (at <4cc8ec075538416496e5db5d391208ac>:0)
UnityEngine.Events.PersistentCall.GetRuntimeCall (UnityEngine.Events.UnityEventBase theEvent) (at <4cc8ec075538416496e5db5d391208ac>:0)
UnityEngine.Events.PersistentCallGroup.Initialize (UnityEngine.Events.InvokableCallList invokableList, UnityEngine.Events.UnityEventBase unityEventBase) (at <4cc8ec075538416496e5db5d391208ac>:0)
UnityEngine.Events.UnityEventBase.RebuildPersistentCallsIfNeeded () (at <4cc8ec075538416496e5db5d391208ac>:0)
UnityEngine.Events.UnityEventBase.PrepareInvoke () (at <4cc8ec075538416496e5db5d391208ac>:0)
UnityEngine.Events.UnityEvent.Invoke () (at <4cc8ec075538416496e5db5d391208ac>:0)
UnityEngine.UI.Button.Press () (at C:/Program Files/2020.1.0f1/Editor/Data/Resources/PackageManager/BuiltInPackages/com.unity.ugui/Runtime/UI/Core/Button.cs:68)
UnityEngine.UI.Button.OnPointerClick (UnityEngine.EventSystems.PointerEventData eventData) (at C:/Program Files/2020.1.0f1/Editor/Data/Resources/PackageManager/BuiltInPackages/com.unity.ugui/Runtime/UI/Core/Button.cs:110)
UnityEngine.EventSystems.ExecuteEvents.Execute (UnityEngine.EventSystems.IPointerClickHandler handler, UnityEngine.EventSystems.BaseEventData eventData) (at C:/Program Files/2020.1.0f1/Editor/Data/Resources/PackageManager/BuiltInPackages/com.unity.ugui/Runtime/EventSystem/ExecuteEvents.cs:50)
UnityEngine.EventSystems.ExecuteEvents.Execute[T] (UnityEngine.GameObject target, UnityEngine.EventSystems.BaseEventData eventData, UnityEngine.EventSystems.ExecuteEvents+EventFunction`1[T1] functor) (at C:/Program Files/2020.1.0f1/Editor/Data/Resources/PackageManager/BuiltInPackages/com.unity.ugui/Runtime/EventSystem/ExecuteEvents.cs:261)
UnityEngine.EventSystems.EventSystem:Update() (at C:/Program Files/2020.1.0f1/Editor/Data/Resources/PackageManager/BuiltInPackages/com.unity.ugui/Runtime/EventSystem/EventSystem.cs:376)

Buttonのインスペクターの情報

該当のソースコード

C#
1using UnityEngine;
2using UnityEngine.UI;
3public class EmojiMove : MonoBehaviour
4{
5    //最初にクリックされたSpriteのPosition
6    Transform EmojiA;
7　　//二回目にクリックされたSpriteのPosition
8    Transform EmojiB;
9    bool isEmojiA;
10    bool isEmojiB = true;
11    public void ChangePosition()
12    {
13        Vector3 tmpA = EmojiA.transform.position;
14        Vector3 tmpB = EmojiB.transform.position;
15        EmojiA.transform.position = tmpB;
16        EmojiB.transform.position = tmpA;
17    }
18    public void OnClickGetSprite(Button button)
19    {
20        if(isEmojiA == false)
21        {
22            EmojiA = button.transform;
23            isEmojiA = true;
24            isEmojiB = false;
25            Debug.Log(button);
26        }
27        else if(isEmojiB == false)
28        {
29            EmojiB = button.transform;
30            isEmojiB = true;
31            Debug.Log(button);
32        }
33    }
34}