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: how long will a boy take to run round a square field of side 50 meters , if he runs at the rate of 10 km / hr ? 
Options: a ) 52 sec , b ) 45 sec , c ) 72 sec , d ) 25 sec , e ) 39 sec
Example Output: c

Example Input: Problem: to produce an annual income of rs . 800 from a 8 % stock at 90 , what is the amount of stock needed ? 
Options: a ) 10000 , b ) 11000 , c ) 12000 , d ) 13000 , e ) 14000
Example Output: a

Example Input: Problem: what is the cp of rs 100 stock at 9 discount , with 1 / 5 % brokerage ? 
Options: a ) 96.9 , b ) 96.3 , c ) 91.2 , d ) 96.7 , e ) 96.21
Example Output:
c