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

Ex Input:
Problem: find the number of different prime factors of 441 
Options: a ) 4 , b ) 2 , c ) 3 , d ) 5 , e ) 6

Ex Output:
b


Ex Input:
Problem: find the number of different prime factors of 25650 
Options: a ) 4 , b ) 2 , c ) 3 , d ) 5 , e ) 6

Ex Output:
a


Ex Input:
Problem: how many kilograms of pure water is to be added to 100 kilograms of a 30 % saline solution to make it a 10 % saline solution . 
Options: a ) 100 , b ) 200 , c ) 300 , d ) 400 , e ) 500

Ex Output:

b