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: each of the three people individually can complete a certain job in 3, 4, and 6 hours, respectively. what is the lowest fraction of the job that can be done in 1 hour by 2 of the people working together at their respective rates ?
Options: a. 1 / 3, b. 9 / 20, c. 8 / 15, d. 5 / 12, e. 2 / 3

Ex Output:
d


Ex Input:
Problem: a no. when divided by 221 gives a remainder 43, what remainder will beobtained by dividingthe same no. 17 ?
Options: a. 3, b. 6, c. 9, d. 10, e. 12

Ex Output:
c


Ex Input:
Problem: a hall 36 m long and 15 m broad is to be paved with stones, each measuring 2 dm by 5 dm. the number of stones required is :
Options: ['a. 180', 'b. 1800', 'c. 5400', 'd. 18000', 'e. 1.8']

Ex Output:

c