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:. 005 / ? =. 01
Options: a.. 5, b.. 05, c.. 005, d.. 0005, e. none of them
Example Output: a

Example Input: Problem: if the ratio of two number is 6: 7 and lcm of the number is 450 then what is the number.
Options: a. 11, b. 20, c. 25, d. 30, e. 35
Example Output: a

Example Input: Problem: in a race of 1000 m, a can beat by 100 m, in a race of 800 m, b can beat c by 100 m. by how many meters will a beat c in a race of 700 m ?
Options: a. 148.75 m, b. 127.5 m., c. 122.2 m, d. 222.9 m, e. 12289 m
Example Output:
a