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: john found that the average of 15 numbers is 40 . if 12 is added to each number then the mean of number is ? 
Options: a ) 52 , b ) 45 , c ) 65 , d ) 78 , e ) 64
Example Output: a

Example Input: Problem: 0.002 x 0.6 = ? 
Options: a ) 0.0012 , b ) 0.001 , c ) 0.01 , d ) 0.1 , e ) none of these
Example Output: a

Example Input: Problem: what is the 28 th digit to the right of the decimal point in the decimal form of 4 / 11 ? 
Options: a ) 3 , b ) 4 , c ) 5 , d ) 6 , e ) 7
Example Output:
d