Correct option is E
12 years ago, let age of A = 2x years
And, age of C = 2x ×50/100=x years
Difference always remains same between age of A and C
So, 2x -x = 12
x = 12
Present age of A = 2×12+12=36 years
Present age of B = 36 ×3/2=54 years