Detailed Instructions: 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.
Problem:Problem: 9 men working 8 hours per day dig 30 m deep. how many extra men should be put to dig to a depth of 50 m working 6 hours per day ?
Options: a. 33, b. 66, c. 88, d. 11, e. 281
Solution:
d