Detailed Instructions: In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
Q: Problem: at what rate percent per annum will a sum of money double in 16 years ? 
Options: a ) 10.6 % , b ) 3.65 % , c ) 6.25 % , d ) 8.32 % , e ) 11 %
A:
c