The total age of A and B is 12 years more than the total age of B and C. C is how many years younger than A.?  Choose the correct choice from the following choices
A) 16  B) 12  C) 15  D) 20  E) 10

Rationale: "( a + b ) - ( b - c ) = 12 a - c = 12 answer is b"
Answer: B