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: a man gains 40 % by selling an article for a certain price. if he sells it at double the price, the percentage of profit will be.
Options: a. 130 %, b. 180 %, c. 150 %, d. 160 %, e. 170 %
A:
b