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: x does a work in 20 days. y does the same work in 40 days. in how many days they together will do the same work ?
Options: a. 10, b. 12, c. 20, d. 30, e. 13.33
Example Output: e

Example Input: Problem: solution y is 30 percent liquid x and 70 percent water. if 2 kilograms of water evaporate from 6 kilograms of solution y and 2 kilograms of solution y are added to the remaining 4 kilograms of liquid, what percent of this new solution is liquid x ?
Options: a. 33 %, b. 35 1 / 2 %, c. 37 %, d. 40 %, e. 42 %
Example Output: d

Example Input: Problem: on a map the distance between two mountains is 312 inches. the actual distance between the mountains is 136 km. ram is camped at a location that on the map is 34 inch from the base of the mountain. how many km is he from the base of the mountain ?
Options: ['a. 14.83', 'b. 14.81', 'c. 14.8', 'd. 14.82', 'e. 14.12']
Example Output:
d