Here's how my brain handled this one,
Step 1 --> Set up the equation.
A + B + C = Total
Based off the question we can infer the following,
B + C = 60 - 12 = 48, thus B = 24, C = 24.
12 minutes is given to us, and we know 60 minutes are in an hour.
So... 12 + 24 + 24 = 60.
Step 2 --> Use data to relate to what the question is looking for.
They are asking for the ratio of C to A. When we think ratio, think first term as a numerator, second term as denominator. So in this case C/A (C:A), or 24/12 (24/12) which simplifies to 2/1 (or 2:1).
Answer is (C).