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: if w is the product of the integers from 1 to 30 , inclusive , what is the greatest integer k for which 3 ^ k is a factor of w ?
Options: a ) 10 , b ) 12 , c ) 14 , d ) 16 , e ) 18

Ex Output:
c

Ex Input:
Problem: if x ^ 2 + y ^ 2 = 15 and xy = 3 , then ( x y ) ^ 2 =
Options: a ) 8 , b ) 9 , c ) 14 , d ) 17 , e ) 20

Ex Output:
b

Ex Input:
Problem: the milk level in a rectangular box measuring 60 feet by 25 feet is to be lowered by 6 inches . how many gallons of milk must be removed ? ( 1 cu ft = 7.5 gallons )
Options: a ) 100 , b ) 250 , c ) 750 , d ) 5625 , e ) 5635

Ex Output:
d