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: an error 1 % in excess is made while measuring the side of a square. the percentage of error in the calculated area of the square is :
Options: a. 2.01, b. 30.1, c. 3.01, d. 25.01, e. 4.05
Example Output: a

Example Input: Problem: if a and b are the roots of the equation x 2 - 9 x + 9 = 0, then the value of a 2 + b 2 is :
Options: a. 63, b. 24, c. 17, d. 6, e. 5
Example Output: a

Example Input: Problem: john bought a shirt on sale for 25 % off the original price and another 25 % off the discounted price. if the final price was $ 17, what was the price before the first discount ?
Options: a. $ 45.10, b. $ 30.22, c. $ 28.44, d. $ 67.54, e. $ 65.23
Example Output:
b