In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Ex Input:
Problem: a rower whose speed is 2.5 km / hr in still water rows to a certain point upstream and back to the starting point in a river which flows at 0.5 km / hr . what is the rower ' s average speed ( in km / hr ) for the total journey ?
Options: a ) 2.2 , b ) 2.3 , c ) 2.4 , d ) 2.5 , e ) 2.6

Ex Output:
c

Ex Input:
Problem: what least no . must be subtracted from 50248 so that remaining no . is divisible by 20 ?
Options: a ) 3 , b ) 2 , c ) 4 , d ) 8 , e ) 6

Ex Output:
d

Ex Input:
Problem: find the average of first 4 multiples of 11 ?
Options: a ) 10 , b ) 12.6 , c ) 27.5 , d ) 31.3 , e ) 40.8

Ex Output:
c