Q: 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.
Problem: an agent, gets a commission of 2.5 % on the sales of cloth. if on a certain day, he gets rs. 21 as commission, the cloth sold through him on that day is worth
Options: a. 333, b. 500, c. 840, d. 299, e. 132
A:
c