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'.

Example Input: Problem: the present worth of rs . 2310 due years hence , the rate of interest being 15 % per annum , is :
Options: a ) rs . 1440 , b ) rs . 1750 , c ) rs . 1680 , d ) rs . 1840 , e ) none of these
Example Output: c

Example Input: Problem: the banker ' s gain of a certain sum due 2 years hence at 10 % per annum is rs . 24 . the present worth is :
Options: a ) rs . 608 , b ) rs . 6076 , c ) rs . 600 , d ) rs . 602 , e ) rs . 601
Example Output: c

Example Input: Problem: the manufacturing cost of a shoe is rs . 230 and the transportation lost is rs . 500 for 100 shoes . what will be the selling price if it is sold at 20 % gains
Options: a ) s 282 , b ) s 216 , c ) s 220 , d ) s 210 , e ) s 217
Example Output:
a