The correct answer is letter C, in most primates, the inability to move the ear has been replaced by the ability to stand upright on two legs. This is because movement was much of a need to these primates than hunting for food. They needed to be agile to locate specific places where sources of food are abundant.
Make sure you do not use the exact same thing... I recommend you do this "Expiriment" on your own! :) But I hope this helps!
