Given the task definition and input, reply with output. 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: with both valves open, the pool will be filled with water in 48 minutes. the first valve alone would fill the pool in 2 hours. if the second valve emits 50 cubic meters of water more than the first every minute, then what is the capacity w of the pool ?
Options: a. 9000 cubic meters, b. 10500 cubic meters, c. 11750 cubic meters, d. 12000 cubic meters, e. 12500 cubic meters
d