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: 49 a 49 a 49 a 49 x 49 = 7 ?
Options: a ) 4 , b ) 7 , c ) 8 , d ) 10 , e ) none of these

Ex Output:
d

Ex Input:
Problem: a vendor sells 30 percent of the apples he had and throws away 20 percent of the remainder . the next day , the vendor sells 50 percent of the remaining apples and throws away the rest . in total , what percent of his apples does the vendor throw away ?
Options: a ) 40 , b ) 42 , c ) 44 , d ) 46 , e ) 48

Ex Output:
b