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 x is real , find the maximum value of the expression - 2 x ^ 2 + 5 x + 7 . 
Options: a ) 6.125 , b ) 8.125 , c ) 10.125 , d ) 12.125 , e ) 14.125

Ex Output:
c


Ex Input:
Problem: jacob is 39 years old . he is 3 times as old as his brother . how old will jacob be when he is twice as old ? 
Options: a ) 63 , b ) 64 , c ) 65 , d ) 76 , e ) 67

Ex Output:
c


Ex Input:
Problem: if s = x ^ 4 + y ^ 4 = 100 , then the greatest possible value of x is between 
Options: a ) 0 and 3 , b ) 3 and 6 , c ) 6 and 9 , d ) 9 and 12 , e ) 12 and 15

Ex Output:

b