Question

Which additional word in this sentence should be capitalized. One twenty-first-century psychologist with a popular television show is doctor Phil.
A. Century
B. Twenty-First
C. Psychologist
D. Doctor

Answer 1

The answer is D. If doctor was on its own you wouldn't capitalize it, but because it is next to his name you would capitalize the title; doctor. 

Answer 2

good question, i think the answer is D. because it is talking about a doctor, and the doctor is Doctor Phil