Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

For a credit card, it charges 15% compounded monthly. Its effective annual rate is closet to?
Option A:15.78%
Option B:18.85%
Option C:16.08%

Answer: C