Which word and punctuation mark corrects the punctuation error in this sentence?

My appointment is at 3 P.M. with Dr Russell Brown, M.D.

A.
P.M.,

B.
Dr.

C.
M,D

Respuesta :

Well, it isn't A because there should only be a period at the end of P.M. It isn't C because it has to be a period between M and D.

So, the answer has to be B.

Hope this helps!