How to change multiple Objects variable from true to false

I am making a Card Game in Which I want to Make a Card Selected when clicked then make only that card selected and highlighted and all the other cards Deselected, everytime a new card is clicked . My aproach is that on the OnPointerClick event I’ll loop trough the scrollView Content panel childs and then change a bool on each of the childrens except for the one clicked to false. I have the following code. but I Do not know how to select each of the childs “Selected” Variable so i can change it. Every card has the same script.

public void OnPointerClick(PointerEventData eventData)
    {
        for (int i = 0; i < this.transform.parent.childCount; i++)
        {
            if(this.transform.parent.GetChild(i) != this.transform )
            {
                // Do not know how to use the "I" to select an specific object variable "Selected".
                this.transform.GetChild(i).GetComponent(CardModel).selected = false;
                
            }
        }
            if (selected)
        {
            if (cardQuantity > 0)
                image.sprite = Faces[1];
            else if(cardQuantity == 0)
                image.sprite = Faces[3];
        }
        else if(selected == false)
        {
            if (cardQuantity > 0)
                image.sprite = Faces[0];
            else if(cardQuantity == 0)
                image.sprite = Faces[2];
        }

for (var i = 0; i < transform.parent.GetComponentsInChildren().Length; i++)
{
if (transform.parent.GetComponentsInChildren().transform != transform)
{
transform.parent.GetComponentsInChildren().selected = false;
}
}
or
foreach (var cardModel in transform.parent.GetComponentsInChildren())
{
if (cardModel.transform != transform)
{
cardModel.selected = false;
}
}
or
var cardModels = FindObjectsOfType();
foreach (var cardModel in cardModels)
{
if (cardModel.transform != transform)
{
cardModel.selected = false;
}
}