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'.

Input: Consider Input: Problem: how is 4 % expressed as a decimal fraction ? 
Options: a ) 0.4 , b ) 0.04 , c ) 0.004 , d ) 0.0004 , e ) 4

Output: b


Input: Consider Input: Problem: in a certain pond , 40 fish were caught , tagged , and returned to the pond . a few days later , 40 fish were caught again , of which 2 were found to have been tagged . if the percent of tagged fish in the second catch approximates the percent of tagged fish in the pond , what is the approximate number of fish in the pond ? 
Options: a ) 1000 , b ) 625 , c ) 1,250 , d ) 2,500 , e ) 10,000

Output: a


Input: Consider Input: Problem: if it is assumed that 70 percent of those who receive a questionnaire by mail will respond and 300 responses are needed , what is the minimum number of questionnaires that should be mailed ? 
Options: a ) 400 , b ) 428.5 , c ) 480 , d ) 500 , e ) 600


Output: b