You will be given a definition of a task first, then some input of the task.
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 certain debt will be paid in 65 installments from january 1 to december 31 of a certain year. each of the first 20 payments is to be $ 410; each of the remaining payments is to be $ 65 more than each of the first 20 payments. what is the average ( arithmetic mean ) payment that will be made on the debt for the year ?
Options: a. 443, b. 455, c. 465, d. 468, e. 475
Output:
b