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

Example Input: Problem: of the 200 stamps in a collection , 90 are foreign and 60 are more than 10 years old . if 20 stamps are both foreign and more than 10 years old , how many stamps are neither foreign nor more than 10 years old ?
Options: a ) 50 , b ) 70 , c ) 100 , d ) 130 , e ) 150
Example Output: b

Example Input: Problem: what is the units digit of 31 ! + 50 ! + 2 ! + 3 ! ?
Options: a ) 0 , b ) 2 , c ) 4 , d ) 6 , e ) 8
Example Output: e

Example Input: Problem: a certain university will select 1 of 7 candidates eligible to fill a position in the mathematics department and 2 of 7 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 ) 147 , d ) 165 , e ) 315
Example Output:
c