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: an investment yields an interest payment of $ 216 each month . if the simple annual interest rate is 9 % , what is the amount of the investment ? 
Options: a ) $ 28,300 , b ) $ 30,400 , c ) $ 28,800 , d ) $ 32,500 , e ) $ 35,100
A: 
c