Do not get hung up on this. What is an active college student anyway? Use these as only very general guidelines to keep you from going off the rails/ 250 hours/year is a reasonable place to start if you have never done any sort of structured trining plan. That means it would probably be unwise to start at 500 hours or 100 hours. But it does not mean that 200 or 300 might not work for you either.
But…B above is where I would start if you have no clue.
It is better to err on the side of going too low the first than too high and getting inured or over trained or loosing your motivation.
Rather than getting too fixated on a number instead use the information in the books to monitor how you are handling the training. Are you recovering from each day’s training? Are you seeing improvements from week to week and month to month. Once you’ve run through this one you will have a much better idea of what you can handle. But you must keep a log of your training if you hope to learn for this experience.
Scott