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: bottle r contains 350 capsules and costs $ 6.25. bottle t contains 130 capsules and costs $ 2.99. what is the difference between the cost per capsule for bottle r and the cost per capsule for bottle t ?
Options: a. $ 0.25, b. $ 0.12, c. $ 0.0052, d. $ 0.003, e. $ 0.002
c

Problem: a theater box office sold an average ( arithmetic mean ) of 63 tickets per staff member to a particular movie. among the daytime staff, the average number sold per member was 78, and among the evening staff, the average number sold was 60. if there are no other employees, what was the ratio of the number of daytime staff members to the number of evening staff members ?
Options: a. 2: 3, b. 1: 4, c. 1: 5, d. 6: 11, e. 4: 7
c

Problem: company c sells a line of 25 products with an average retail price of $ 1,200. if none of these products sells for less than $ 400, and exactly 10 of the products sell for less than $ 1,000, what is the greatest possible selling price of the most expensive product ?
Options: a. 12000, b. 13000, c. 14000, d. 15000, e. 16000

a