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: an aeroplane covers a certain distance at a speed of 150 kmph in 2 hours. to cover the same distance in 1 2 / 3 hours, it must travel at a speed of :
Options: a. 1300 kmph, b. 160 kmph, c. 180 kmph, d. 1080 kmph, e. none

Output: c


Input: Consider Input: Problem: 1391 x 1391 = ?
Options: a. a. 1951609, b. b. 1951601, c. c. 1951602, d. d. 1951603, e. e. 1934881

Output: e


Input: Consider Input: Problem: the list price of an article is rs. 70. a customer pays rs. 59.22 for it. he was given two successive discounts, one of them being 10 %. the other discount is ?
Options: a. 8 %, b. 7 %, c. 10 %, d. 12 %, e. 6 %


Output: e