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: a seller of used cars has 16 cars to sell and each of his clients selected 2 cars that he liked most . if each car was selected exactly thrice , how many clients visited the garage ? 
Options: a ) 8 , b ) 10 , c ) 12 , d ) 14 , e ) 24
Example Output: e

Example Input: Problem: for a certain exam , a score of 60 was 2 standard deviations below mean and a score of 100 was 3 standard deviations above mean . what was the mean score for the exam ? 
Options: a ) 74 , b ) 76 , c ) 78 , d ) 80 , e ) 82
Example Output: b

Example Input: Problem: ( 0.15 ) ( power 3 ) - ( 0.06 ) ( power 3 ) / ( 0.15 ) ( power 2 ) + 0.009 + ( 0.06 ) ( power 2 ) is : 
Options: a ) 0.09 , b ) 0.08 , c ) 0.1 , d ) 0.07 , e ) none of them
Example Output:
a