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

Ex Input:
Problem: in what ratio must a grocer mix two varieties of pulses costing rs . 15 and rs . 20 per kg respectively so as to get a mixture worth rs . 16.50 per kg ? 
Options: a ) 3 : 7 , b ) 5 : 7 , c ) 7 : 3 , d ) 7 : 5 , e ) none

Ex Output:
c


Ex Input:
Problem: what number has a 3 : 4 ratio to the number 400 ? 
Options: a ) 130 , b ) 100 , c ) 200 , d ) 300 , e ) 120

Ex Output:
d


Ex Input:
Problem: income and expenditure of a person are in the ratio 5 : 4 . if the income of the person is rs . 20000 , then find his savings ? 
Options: a ) rs . 3600 , b ) rs . 4000 , c ) rs . 3639 , d ) rs . 3632 , e ) rs . 3602

Ex Output:

b