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: the roof of an apartment building is rectangular and its length is 3 times longer than its width. if the area of the roof is 588 feet squared, what is the difference between the length and the width of the roof ?
Options: a. 28., b. 40., c. 42., d. 44., e. 46.
A:
a