Given the task definition and input, reply with output. 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: a person saved $ 10 in buying an item on sale. if he spent $ 500 for the item, approximately how much percent he saved in the transaction ?
Options: a. 8 %, b. 10 %, c. 2 %, d. 5 %, e. 6 %

c