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

Ex Input:
Problem: the compound ratio of 5 : 6 , 3 : 2 and 4 : 5 is ? 
Options: a ) 3 : 5 , b ) 2 : 7 , c ) 1 : 1 , d ) 1 : 4 , e ) none

Ex Output:
c


Ex Input:
Problem: an order was placed for the supply of a carper whose length and breadth were in the ratio of 3 : 2 . subsequently , the dimensions of the carpet were altered such that its length and breadth were in the ratio 7 : 3 but were was no change in its parameter . find the ratio of the areas of the carpets in both the ? 
Options: a ) 8 : 6 , b ) 8 : 7 , c ) 8 : 1 , d ) 8 : 2 , e ) 8 : 4

Ex Output:
b


Ex Input:
Problem: a certain university will select 1 of 5 candidates eligible to fill a position in the mathematics department and 2 of 8 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 ) 138 , b ) 140 , c ) 142 , d ) 145 , e ) 148

Ex Output:

b