B

Analysis In the calculation of compound interest, the interest rate cycle is usually in years, which can be the same as or different from the interest-bearing cycle. When the interest period is less than one year, the concepts of nominal interest rate and effective interest rate appear. The concept of compound interest does not appear clearly in this issue, but because interest is calculated quarterly, it is actually compound interest. The correct formula is: (1+12%/4) 4-1=12.55%. In the alternative answer. A does not consider compound interest, and C and D interest on a monthly or four-month basis, which is inconsistent with the meaning of the question. The correct choice in this question is B.