Which of these sentences uses correct capitalization

B, i believe (if i can recall correctly) that president should only be capitalized before the name of a president e.g. President Franklin. D. Roosevelt

Correct Capitalization: Franklin D. Roosevelt was the first President to appear on television, and he did it in 1919.

The answer is C.

A is incorrect - The 'd' in "Franklin d. Roosevelt" needs to be capitalized (since it's the President's middle name)
B is incorrect - The letter 'p' in "president" needs to be capitalized 
D is incorrect - The word "First" doesn't need to be capitalized because it's a number