In this task, you need to provide the correct option for a given problem from the provided options.

Ex Input:
Problem: a certain university will select 1 of 4 candidates eligible to fill a position in the mathematics department and 2 of 10 candidates eligible to fill 2 identical positions in the computer science department . if none of the candidates is eligible for a position in both departments , how many different sets of 3 candidates are there to fill the 3 positions ? 
Options: a ) 42 , b ) 70 , c ) 140 , d ) 180 , e ) 315

Ex Output:
d


Ex Input:
Problem: the sub - duplicate ratio of 25 : 49 is 
Options: a ) 4 : 3 , b ) 5 : 7 , c ) 6 : 4 , d ) 1 : 4 , e ) 2 : 3

Ex Output:
b


Ex Input:
Problem: income and expenditure of a person are in the ratio 5 : 4 . if the income of the person is rs . 17000 , then find his savings ? 
Options: a ) 3600 , b ) 3400 , c ) 3608 , d ) 3602 , e ) 3603

Ex Output:

b