Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

Ex Input:
Problem: the ratio of the present age of viju to that of aju is 7: 2. 4 years from now, the ratio of the ages of viju to aju will be 5: 2. what was viju age 5 years ago ? ( rbi assistant 2015 )
Options: a. 24, b. 18, c. 12, d. 16, e. 13

Ex Output:
d


Ex Input:
Problem: in a fuel station the service costs $ 1.65 per car, every liter of fuel costs 0.65 $. assuming that a company owns 12 cars and that every fuel tank contains 55 liters and they are all empty, how much money total will it cost to fuel all cars ?
Options: a. 320 $, b. 380 $, c. 420 $, d. 448.8 $, e. 480 $

Ex Output:
d


Ex Input:
Problem: the height of the wall is 6 times its width and length of the wall is 7 times its height. if the volume of the wall be 86436 cu. m. its width is
Options: a. 4 m, b. 5 m, c. 6 m, d. 7 m, e. 8 m

Ex Output:

d