Answer:
C to ensure he has enough caffeine
Explanation:
You need energy to think and do and the other answers don't make much sense. Ex: He wouldn't avoid taking breaks because you need breaks, it's required, an essential of life pretty much. B makes no sense at all because why would you avoid leaving to get food? And a makes it difficult to decide whether it's A or D but if you really think about it, it doesn't make sense to bring food to enjoy yourself while in a studying session.
Hope this Helps! :)
