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.

Input: Consider Input: Problem: a and b invests rs. 2500 and rs. 4000 respectively in a business. if a doubles his capital after 6 months. in what ratio should a and b divide that year ' s profit ?
Options: a. 11: 5, b. 15: 16, c. 15: 2, d. 9: 9, e. 11: 1

Output: b


Input: Consider Input: Problem: a train 50 m long takes 6 sec to cross a man walking at 5 kmph in a direction opposite to that of the train. find the speed of the train ?
Options: a. 15 kmph, b. 25 kmph, c. 35 kmph, d. 45 kmph, e. 55 kmph

Output: b


Input: Consider Input: Problem: what is the units digit of 17 ^ 83 × 13 ^ 82 × 11 ^ 67 ?
Options: a. 4, b. 5, c. 6, d. 7, e. 8


Output: a