Which One of the Following Statement Is True for a Regular

Multiple Choice

Which one of the following statement is true for a regular language L over {a} whose minimal finite state automation has two states?

A) L must be either {an I n is odd} or {an I n is even}
B) L must be {an I n is odd}
C) L must be {an I n is even}
D) L must be {an I n = 0}