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: if 5400 mn = k ^ 4 , where m , n , and k are positive integers , what is the least possible value of m + 2 n ? 
Options: a ) 11 , b ) 18 , c ) 20 , d ) 25 , e ) 40
Example Output: e

Example Input: Problem: a cyclist rides a bicycle 8 km at an average speed of 10 km / hr and again travels 10 km at an average speed of 8 km / hr . what is the average speed for the entire trip ? 
Options: a ) 9.28 , b ) 8.48 , c ) 8.78 , d ) 8.98 , e ) 9.18
Example Output: c

Example Input: Problem: in the seaside summer camp there are 50 children . 90 % of the children are boys and the rest are girls . the camp administrator decided to make the number of girls only 5 % of the total number of children in the camp . how many more boys must she bring to make that happen ? 
Options: a ) 50 . , b ) 45 . , c ) 40 . , d ) 30 . , e ) 25 .
Example Output:
a