D
One of the most striking things to me is just HOW big of a man Arnold really is when standing next to the other guys. His shoulder width just dwarfs everybody. Also his arms make everyone elses look like 17" - even Mentzers. That was kinda surprising to me - Mentzer, Coe and Callendar had some thick arms, but they look like a childs compared to Arnie. Just imagine if he didn't retire in '75. He was only 28 at the time. Hypothetically and realistically, he could have continued winning at LEAST thru 1983 since he owned Franco & Zane, and nobody doubts he would have beaten Dickerson and Samir. That would have been 14 O's- a record that probably would have never been broken.
I have wondered this myself. As great as Arnie was/is as you said, Imagine what he COULD have accomplished had he not chosen to move on in his prime. Easily well into double digits as far as Mr O titles.