unity raycast to mouse position

//code for raycast
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
RaycastHit hitInfo;
Physics.Raycast(ray, out hitInfo);
GameObject hitObject = hitInfo.transform.root.gameObject;

//code for getting a paren'ts transform
private GameObject GetRoot(GameObject gameObject)
{
    Transform t = gameObject.transform;
    while (t.parent != null)
    {
        t = t.parent;
    }
    return t.gameObject;
}