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'.

Example Input: Problem: in a theater , the first row has 12 seats and each row has 2 more seats than previous row . if the last row has 48 seats , what is the total number of seats in the theater ? 
Options: a ) 550 , b ) 570 , c ) 590 , d ) 610 , e ) 630
Example Output: b

Example Input: Problem: joan and karl each bought a telescopes and the sum of their purchases was $ 400 . if twice of what joan paid was $ 74 more than what karl paid , what did joan pay for her telescope ? 
Options: a ) $ 150 , b ) $ 152 , c ) $ 154 , d ) $ 156 , e ) $ 158
Example Output: e

Example Input: Problem: when 5 is added to half of one - third of one - fifth of a number , the result is one - fifteenth of the number . find the number ? 
Options: a ) 32 , b ) 150 , c ) 60 , d ) 27 , e ) 11
Example Output:
b