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'.

Ex Input:
Problem: if each edge of cube increased by 30 % , the percentage increase in 
Options: a ) 69 , b ) 72 , c ) 64 , d ) 61 , e ) 75

Ex Output:
a


Ex Input:
Problem: the calendar of the year 2028 can be used again in the year ? 
Options: a ) 2041 , b ) 1951 , c ) 2056 , d ) 1971 , e ) 1973

Ex Output:
c


Ex Input:
Problem: 20 one identical machines , running continuously at the same constant rate , take 9 days to complete a shipment . how many additional machines , each running at the same constant rate , would be needed to reduce the time required to complete a shipment by two days ? 
Options: a ) 2 , b ) 3 , c ) 4 , d ) 6 , e ) 9

Ex Output:

d