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: find the smallest positive integer n such that 11 n - 1 is divisible by 105 . 
Options: a ) 3 , b ) 4 , c ) 5 , d ) 6 , e ) 7

Ex Output:
d


Ex Input:
Problem: an italian sausage is 8 inches long . how many pieces of sausage can be cut from the 8 - inch piece of sausage if each piece is to be 2 / 3 of an inch ? 
Options: a ) 12 , b ) 32 , c ) 22 , d ) 15 , e ) 20

Ex Output:
a


Ex Input:
Problem: the average age of 31 students in a group is 16 years . when teacher ' s age is included to it , the average increases by one . what is the teacher ' s age in years ? 
Options: a ) 31 , b ) 36 , c ) 48 , d ) 45 , e ) 57

Ex Output:

c