A proton situated in a magnetic field is observed to travel in a circular path. The positions of the proton at times T, 2T, and 3T are shown in the figure below. Which vector best represents the instantaneous velocity of the proton at t=2T?

A proton situated in a magnetic field is observed to travel in a circular path. The positions of the proton at times T, 2T, and 3T are shown in the figure below. t-3T t=2T t- T Which vector best represents the instantaneous velocity of the proton at t=2T? A. B. C. D. E