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

Example Input: Problem: the ratio of the present ages of two friends is 2 : 3 and 6 years back , the ratio was 1 : 3 . what will be the ratio of their ages after 4 years ? 
Options: a ) 1 : 4 , b ) 3 : 4 , c ) 1 : 2 , d ) 3 : 1 , e ) 3 : 2
Example Output: b

Example Input: Problem: 90 people are attending a newspaper conference . 45 of them are writers and more than 38 are editors . of the people at the conference , x are both writers and editors and 2 x are neither . what is the largest possible number of people who are both writers and editors ? 
Options: a ) 18 , b ) 16 , c ) 12 , d ) 10 , e ) 6
Example Output: e

Example Input: Problem: a factory produces 1 defective bulb out of 10 bulbs a yr . if it produces 870 bulbs a yr , how many defective bulbs are produced ? 
Options: a ) 84 , b ) 85 , c ) 86 , d ) 87 , e ) 88
Example Output:
d