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 merchant sells an item at a 20 % discount, but still makes a gross profit of 20 percent of the cost. what percent of the cost would the gross profit on the item have been if it had been sold without the discount ?
Options: a. 20 %, b. 40 %, c. 50 %, d. 60 %, e. 75 %
Example Output: c

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: if a ( a + 7 ) = 60 and b ( b + 7 ) = 60, where a ≠ b, then a + b =
Options: a. − 7, b. − 2, c. 2, d. 46, e. 48
Example Output:
a