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.

[EX Q]: Problem: income and expenditure of a person are in the ratio 7: 6. if the income of the person is rs. 14000, then find his savings ?
Options: a. 500, b. 1000, c. 1500, d. 2000, e. 2500
[EX A]: d

[EX Q]: Problem: dropbox charges $ 3.10 for first 1 / 5 of a month for 500 gb storage, plus $ 0.40 for each additional 1 / 5 of a month. what would dropbox charge for a data storage of 500 gb for 8 months ?
Options: a. $ 15.60, b. $ 16.00, c. $ 17.80, d. $ 18.70, e. $ 19.10
[EX A]: d

[EX Q]: Problem: in n is a positive integer less than 200, and 14 n / 60 is an integer, then n has how many different positive prime factors a ?
Options: a. 2, b. 3, c. 5, d. 6, e. 8
[EX A]:
b