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.

Let me give you an example: Problem: a multiple choice test consists of 4 questions, and each question has 5 answer choices. in how many r ways can the test be completed if every question is unanswered ?
Options: a. 24, b. 120, c. 625, d. 720, e. 1024
The answer to this example can be: c
Here is why: 5 choices for each of the 4 questions, thus total r of 5 * 5 * 5 * 5 = 5 ^ 4 = 625 ways to answer all of them. Hence, the answer is c.

OK. solve this:
Problem: two cars a and b start from boston and new york respectively simultaneously and travel towards each other at constant speeds along the same route. after meeting at a point between boston and new york the two cars a and b proceed to their respective destinations of new york and boston. car a reaches new york 80 minutes after the two cars have met and car b reaches boston 90 minutes after they have met. how long did car a take to cover the distance between boston and new york ?
Options: a. 1 hour, b. 1 hour 10 minutes, c. 2 hours 30 minutes, d. 1 hour 40 minutes, e. 2 hours 20 minutes
Answer:
e