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: the batting average of a particular batsman is 60 runs in 46 innings. if the difference in his highest and lowest score is 140 runs and his average excluding these two innings is 58 runs, find his highest score.
Options: a. 179, b. 367, c. 269, d. 177, e. 174
Example Output: e

Example Input: Problem: a 11 % stock yields 8 %. the market value of the stock is :
Options: a. rs. 72, b. rs. 137.50, c. rs. 112.50, d. rs. 116.50, e. none of these
Example Output: b

Example Input: Problem: the ratio, by volume, of soap to alcohol to water in a certain solution is 20: 50: 80. the solution will be altered so that the ratio of soap to alcohol is doubled while the ratio of soap to water is halved. if the altered solution will contain 100 cubic centimeters of alcohol, how many cubic centimeters of water will it contain ?
Options: a. 520, b. 640, c. 700, d. 750, e. 800
Example Output:
b