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'.

Ex Input:
Problem: for any integer k greater than 1 , the symbol k * denotes the product of all integers between 1 and k , inclusive . if k * is a multiple of 315 what is the least possible value of k ? 
Options: a ) 5 , b ) 7 , c ) 9 , d ) 11 , e ) 13

Ex Output:
b


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

Ex Output:
d


Ex Input:
Problem: the average weight of 8 persons increases by 2.5 kg when a new person comes in place of one of them weighing 65 kg . what might be the weight of the new person ? 
Options: a ) 76 kg , b ) 76.5 kg , c ) 85 kg , d ) 90 kg , e ) none

Ex Output:

c