to make the food less messy to eat to preserve the food for extended flights to increase the food's nutritional content to keep the food from floating off the plate
I gave my students this multiple choice question: Why is some food dehydrated for astronauts to eat in space?

Only one answer is correct among these 4 choices:
- to make the food less messy to eat
- to preserve the food for extended flights
- to increase the food's nutritional content
- to keep the food from floating off the plate

Could you tell me which one is correct?

to preserve the food for extended flights