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: if the average ( arithmetic mean ) of a and b is 45 and the average of b and c is 80, what is the value of c − a ?
Options: a. 25, b. 60, c. 90, d. 140, e. it can not be determined from the information given.
Example Output: b

Example Input: Problem: if the radius of a cylinder is made 3 times and so is the height, what is the new volume of the cylinder divided by the old one ?
Options: a. 27., b. 2., c. 6., d. 4., e. 10.
Example Output: a

Example Input: Problem: a computer manufacturer produces a certain electronic component at a cost of $ 80 per component. shipping costs for delivering the components are $ 3 per unit. further, the manufacturer has costs of $ 16,500 a month related to the electronic component regardless of how many it produces. if the manufacturer produces and sells 150 components a month, what is the lowest price it can sell them for such that the costs do n ' t exceed the revenues ?
Options: a. $ 28, b. $ 82, c. $ 110, d. $ 138, e. $ 193
Example Output:
e