how to check if a UIViewController is in the middle of being animated on screen

how to check if a UIViewController is in the middle of being animated on
screen

Can I see somehow from, say UIViewController A, if UIViewController B is
in the middle of the animation of being presented on screen?
I know I can add code to UIViewController B (for example some boolean
value used in viewWillAppear, viewDidAppear or in the completion block of
presentViewController:animated:completion:), but I also have
UIViewController C, D, E, F etc. So I prefer to check this only in
UIViewController A if possible.
Does anyone if this can be done and in case of 'yes, it can', how..?
Thanks in advance.