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 a * b * c = ( ( a + 2 ) ( b + 3 ) ) / ( c + 1 ) , find the value of 6 * 15 * 2 .
Options: a ) 8 , b ) 5 , c ) 11 , d ) 3 , e ) 4
Example Output: e

Example Input: Problem: what is the next number : 2 , 17 , 257 , __
Options: a ) 2977 , b ) 3837 , c ) 4097 , d ) 4847 , e ) 5387
Example Output: c

Example Input: Problem: the average weight of a , b , c is 45 kg . the avg wgt of a & b be 40 kg & that of b , c be 43 kg . find the wgt of b .
Options: a ) 36 kg , b ) 84 kg , c ) 31 kg , d ) 45 kg , e ) 12 kg
Example Output:
b