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.

Example Input: Problem: a library branch originally contained 18360 volumes, 30 % of which were fiction novels. 1 / 3 of the volumes were transferred to another location and 1 / 5 of the volumes transferred were fiction novels. what percent of the remaining collection was fiction novels ?
Options: a. 2.5 %, b. 17.67 %, c. 28.3 %, d. 36 %, e. 73.6 %
Example Output: d

Example Input: Problem: cost is expressed by the formula tb ^ 4. if b is doubled, the new cost w is what percent of the original cost ?
Options: a. w = 200, b. w = 600, c. w = 800, d. w = 1600, e. w = 50
Example Output: d

Example Input: Problem: a man opens a shop. he buys water bottles for 50 cents each, fruit for 25 cents each, and snacks for a dollar each. he wants to start a bundle of selling a bottle a water, 3 snacks and 2 fruits for d dollars. every 5 th bundle sold will be sold for 2 dollars and a complimentary snack at the owner ' s expense. what should he charge at least to not lose any money ?
Options: a. 4.6, b. 3.0, c. 4.1, d. 3.2, e. 2.9
Example Output:
a