B would be equal to 3/6.
Fractions with the same denominator are able to add together on the numerator.
A is not correct because it is equal to 6/6, which is equivalent to 1. However, we are looking for 3/6, or 1/2 of a 1.
C is not correct either because 3/3 is also equal to 1.
D is also not correct because it is equal to 2. 3/3 = 1
3/3 + 3/3 = 6/3 = 2