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: income and expenditure of a person are in the ratio 7: 6. if the income of the person is rs. 14000, then find his savings ?
Options: a. 500, b. 1000, c. 1500, d. 2000, e. 2500
Example Output: d

Example Input: Problem: the cash realised on selling a 14 % stock is rs. 109.25, brokerage being 1 / 4 % is ?
Options: a. 366, b. 106, c. 102, d. 109, e. 122
Example Output: d

Example Input: Problem: what percent of 250 is 45 ?
Options: a. 0.25 %, b. 18 %, c. 25 %, d. 40 %, e. 250 %
Example Output:
b