Definition: 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: Problem: a reduction of 40 % in the price of oil enables a house wife to obtain 8 kgs more for rs. 2400, what is the reduced price for kg ?
Options: a. rs. 120, b. rs. 125, c. rs. 130, d. rs. 135, e. rs. 140
Output:
a