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: a man walking at a rate of 15 km / hr crosses a bridge in 10 minutes . the length of the bridge is ?
Options: a ) 500 m , b ) 1110 m , c ) 950 m , d ) 1000 m , e ) 1300 m
Example Output: a

Example Input: Problem: two numbers are respectively 50 % and 100 % more than a third number . the percentage that is first of the second is ?
Options: a ) 65 % , b ) 83 % , c ) 27 % , d ) 42 % , e ) 75 %
Example Output: e

Example Input: Problem: what is 15 percent of rs . 34 ?
Options: a ) rs . 3.40 , b ) rs . 3.75 , c ) rs . 4.50 , d ) rs . 5.10 , e ) none
Example Output:
d