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 collection of books went on sale, and 2 / 3 of them were sold for $ 3.50 each. if none of the 40 remaining books were sold, what was the total amount received for the books that were sold ?
Options: a. $ 180, b. $ 250, c. $ 260, d. $ 280, e. $ 300
A:
d