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 fruit seller sells mangoes at the rate of rs. 12 per kg and thereby loses 10 %. at what price per kg, he should have sold them to make a profit of 15 % ?
Options: a. rs. 11.81, b. rs. 12, c. rs. 15.33, d. rs. 12.31, e. none
Output:
c