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.

Example Input: Problem: 50 % of a number is more than 40 % of 120 by 180. find the number ?
Options: a. 456, b. 480, c. 420, d. 445, e. 320
Example Output: a

Example Input: Problem: john can complete a given task in 18 days. jane will take only 12 days to complete the same task. john and jane set out to complete the task by beginning to work together. however, jane was indisposed 6 days before the work got over. in how many days did the work get over from the time john and jane started to work on it together ?
Options: a. 11, b. 34 / 5, c. 44 / 5, d. 54 / 5, e. 12
Example Output: d

Example Input: Problem: x and y started a business by investing rs. 36000 and rs. 42000 respectively after 4 months z joined in the business with an investment of rs. 48000, then find share of z in the profit of rs. 14190 ?
Options: a. 3200, b. 4000, c. 3250, d. 4128, e. 3985
Example Output:
d