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

Example Input: Problem: jo ' s collection contains us , indian and british stamps . if the ratio of us to indian stamps is 4 to 2 and the ratio of indian to british stamps is 5 to 1 , what is the ratio of us to british stamps ? 
Options: a ) 5 : 1 , b ) 10 : 5 , c ) 15 : 2 , d ) 20 : 2 , e ) 25 : 2
Example Output: d

Example Input: Problem: how many different positive integers are factors of 64 ? 
Options: a ) 10 , b ) 12 , c ) 14 , d ) 16 , e ) 18
Example Output: d

Example Input: Problem: the ratio of 3 numbers is 5 : 3 : 4 and their sum is 108 . the second number of the 3 numbers is ? 
Options: a ) 23 , b ) 27 , c ) 30 , d ) 32 , e ) 34
Example Output:
b