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: the average marks of a class of 40 students is 44 and that of another class of 45 students is 70 . find the average marks of all the students ? 
Options: a ) 52.6 , b ) 52.4 , c ) 52.1 , d ) 69.5 , e ) 52.9
Example Output: d

Example Input: Problem: the contents of a certain box consist of 48 apples and 30 kiwis . how many kiwis must be added to the box so that exactly 30 % of the pieces of fruit in the box will be apples ? 
Options: a ) 90 , b ) 72 , c ) 82 , d ) 54 , e ) 65
Example Output: c

Example Input: Problem: if 2 x + y = 7 and x + 2 y = 5 , then 7 xy / 3 = ? 
Options: a ) a ) 1 , b ) b ) 2 , c ) c ) 7 , d ) d ) 18 / 5 , e ) e ) 4
Example Output:
c