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: what is the least number which should be added to 5432 so that the sum is exactly divisible by 5 , 6 , 4 , and 3 ? 
Options: a ) 16 , b ) 22 , c ) 28 , d ) 34 , e ) 40
Example Output: c

Example Input: Problem: the difference between a 7 digit number and the number formed by reversing its digit is not a multiple of 
Options: a ) 121 , b ) 11 , c ) 9 , d ) 10 , e ) 3
Example Output: a

Example Input: Problem: a , b and c have rs . 600 between them , a and c together have rs . 250 and b and c rs . 450 . how much does c have ? 
Options: a ) 70 , b ) 90 , c ) 120 , d ) 100 , e ) 140
Example Output:
d