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 s is the sum of reciprocals of a list of consecutive integers from 55 to 64, inclusive, s is approximately equal to
Options: a. 0.16, b. 0.2, c. 0.3, d. 0.4, e. 0.5
Example Output: a

Example Input: Problem: if 50 apprentices can finish a job in 4 hours, and 30 journeymen can finish the same job in 8 hours, how much of the job should be completed by 10 apprentices and 15 journeymen in one hour ?
Options: a. 1 / 9, b. 29 / 180, c. 9 / 80, d. 1 / 5, e. 39 / 121
Example Output: c

Example Input: Problem: a “ palindromic integer ” is an integer that remains the same when its digits are reversed. so, for example, 43334 and 516615 are both examples of palindromic integers. how many 6 - digit palindromic integers are both even and greater than 500,000 ?
Options: a. 160, b. 200, c. 240, d. 300, e. 480
Example Output:
b