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: if a is a positive integer , and if the units digit of a ^ 2 is 9 and the units digit of ( a + 1 ) ^ 2 is 4 , what is the units x digit of ( a + 2 ) ^ 2 ? 
Options: a ) 1 , b ) 3 , c ) 5 , d ) 6 , e ) c . 14

Ex Output:
a


Ex Input:
Problem: in a group of ducks and cows , the total number of legs are 8 more than twice the no . of heads . find the total no . of buffaloes . 
Options: a ) 5 , b ) 4 , c ) 6 , d ) 3 , e ) 2

Ex Output:
b


Ex Input:
Problem: mike took a taxi to the airport and paid $ 2.50 to start plus $ 0.25 per mile . annie took a different route to the airport and paid $ 2.50 plus $ 5.00 in bridge toll fees plus $ 0.25 per mile . if each was charged exactly the same amount , and annie ' s ride was 16 miles , how many miles was mike ' s ride ? 
Options: a ) 32 , b ) 36 , c ) 40 , d ) 44 , e ) 48

Ex Output:

b