First, you need to simplify these fractions:
4/12 = 1/3
A. is definitely the same as 4/12.
B: 12/30 = 2/5
C: 8/24 = 1/3 - this is also the same as 4/12
D: 16/48 = 1/3 this is also the same as 4/12
This means that the fraction not equivalent to 4/12 is B. 12/30