Changing UIButton of a ViewController from another ViewController in swift 3 - ios

Question

I have two ViewController say A, B and C A contains arrays of UIBUtton and a function. The function uses a tag to identify the button pressed, There is a button (the red x button) that displays B ontop of A with a menu, when the menu (i.e B) is clicked it removes controller B before navigating / push to view controller C. This works well.
The red button in controller A rotates from "x" to "+" when clicked. If its "+" the controller B is displayed if "x" its removed. The problem is when am on C and I go back the button still remains as "+" instead of "x" the default state.. I have tried a lot solution from SO using delegate but none tend to solve my problem. Below are the screenshot and code have worked on so far
View Controller A
#IBAction func didPressTab(_ sender: UIButton) {
if (sender.tag != 2) {
let previousIndex = selectedIndex
selectedIndex = sender.tag
buttons[previousIndex].isSelected = false
let previousVC = contentViewControlers[previousIndex]
previousVC.willMove(toParentViewController: nil)
previousVC.view.removeFromSuperview()
previousVC.removeFromParentViewController()
sender.isSelected = true
let vc = contentViewControlers[selectedIndex]
addChildViewController(vc)
vc.view.frame = contentView.bounds
contentView.addSubview(vc.view)
vc.didMove(toParentViewController: self)
buttons[2].setImage(#imageLiteral(resourceName: "cancel"), for: .normal)
toogle = false
} else {
selectedIndex = sender.tag
//buttons[selectedIndex].isSelected = false
if (!toogle) {
buttons[selectedIndex].setImage(#imageLiteral(resourceName: "add"), for: .normal)
buttons[selectedIndex].isSelected = true
let vc = contentViewControlers[selectedIndex]
addChildViewController(vc)
vc.view.frame = contentView.bounds
contentView.addSubview(vc.view)
vc.didMove(toParentViewController: self)
toogle = true
} else {
buttons[selectedIndex].setImage(#imageLiteral(resourceName: "cancel"), for: .normal)
let previousVC = contentViewControlers[selectedIndex]
previousVC.willMove(toParentViewController: nil)
previousVC.view.removeFromSuperview()
previousVC.removeFromParentViewController()
toogle = false
}
}
}
func normalizeView() {
buttons[2].setImage(#imageLiteral(resourceName: "cancel"), for: .normal)
toogle = false
}
ViewController B (When the menu is clicked)
#IBAction func menuClicked(_ sender: UIButton) {
if (sender.tag == 0) {
let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let CViewController = storyBoard.instantiateViewController(withIdentifier: "pass_code") as! CViewController
present(CViewController, animated: true, completion: nil)
} else if (sender.tag == 1) {
let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let profileViewController = storyBoard.instantiateViewController(withIdentifier: "profile") as! ProfileViewController
present(profileViewController, animated: true, completion: nil)
}
let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let AViewControler = storyBoard.instantiateViewController(withIdentifier: "dashboard") as! AViewController
//This is the code that tries to change the button from "+" back to default "x" but trows an error that an optional value is nil
AViewControler.normalizeView()
//This removes A from the view
willMove(toParentViewController: nil)
self.view.removeFromSuperview()
removeFromParentViewController()
}