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 number is doubled and 6 is added . if resultant is trebled , it becomes 72 . what is that number 
Options: a ) 8 , b ) 10 , c ) 9 , d ) 14 , e ) 16
Example Output: c

Example Input: Problem: each child has 6 crayons and 12 apples . if there are 12 children , how many crayons are there in total ? 
Options: a ) 22 , b ) 65 , c ) 72 , d ) 78 , e ) 90
Example Output: c

Example Input: Problem: a number a is squared and then multiplied by negative 6 . the result of this operation is equal to 3 times the sum of fourth times a and two . what is one possible value of a ? 
Options: a ) 2 , b ) 3 , c ) 4 , d ) 1 , e ) 5
Example Output:
d