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: 123 : 36 : : 221 : ?
Options: a ) 52 , b ) 69 , c ) 72 , d ) 25 , e ) 32

Ex Output:
d

Ex Input:
Problem: p has $ 42 more than what q and r together would have had if both b and c had 1 / 8 of what p has . how much does p have ?
Options: a ) $ 44 , b ) $ 48 , c ) $ 52 , d ) $ 56 , e ) $ 60

Ex Output:
d

Ex Input:
Problem: a 6 - liter solution is 40 % alcohol . how many liters of pure alcohol must be added to produce a solution that is 50 % alcohol ?
Options: a ) 1.2 , b ) 1.5 , c ) 1.8 , d ) 2.1 , e ) 2.4

Ex Output:
a