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

Example Input: Problem: a 30 kg metal bar made of alloy of tin and silver lost 3 kg of its weight in the water . 10 kg of tin loses 1.375 kg in the water ; 5 kg of silver loses 0.375 kg . what is the ratio of tin to silver in the bar ? 
Options: a ) 1 / 4 , b ) 2 / 5 , c ) 1 / 2 , d ) 3 / 5 , e ) 2 / 3
Example Output: e

Example Input: Problem: in a graduating class of 236 students , 144 took geometry and 119 took biology . what is the difference between the greatest possible number and the smallest possible number of students that could have taken both geometry and biology ? 
Options: a ) 144 , b ) 119 , c ) 113 , d ) 117 , e ) 31
Example Output: d

Example Input: Problem: a firm is comprised of partners and associates in a ratio of 2 : 63 . if 50 more associates were hired , the ratio of partners to associates would be 1 : 34 . how many partners are currently in the firm ? 
Options: a ) 5 , b ) 10 , c ) 12 , d ) 20 , e ) 25
Example Output:
d