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

Example Input: Problem: find the fraction which has the same ratio to 2 / 6 that 3 / 4 has to 1 / 2
Options: a ) 1 / 2 , b ) 2 / 5 , c ) 6 / 8 , d ) 9 / 4 , e ) 7 / 5
Example Output: a

Example Input: Problem: income and expenditure of a person are in the ratio 5 : 4 . if the income of the person is rs . 15000 , then find his savings ?
Options: a ) 3600 , b ) 3607 , c ) 3608 , d ) 3602 , e ) 3000
Example Output: e

Example Input: Problem: a garrison of 400 men had a provision for 31 days . after 25 days 320 persons re - enforcement leave the garrison . find the number of days for which the remaining ration will be sufficient ?
Options: a ) 65 days , b ) 30 days , c ) 10 days , d ) 16 days , e ) 18 days
Example Output:
b