Given a fact, create a question that can be answered using the fact. Construct the question such that it is unambiguous, has a unique answer and the answer can be given using the fact.

Fact: as ability to preserve food increases , the ability to transport food increases
if a student needs to travel with their lunch for long distances, which of these would have the freshest meal?

Fact: a magnet attracts ferromagnetic metals through magnetism
A magnet would attract a?

Fact: ethanol sometimes is made of corn

Ethanol sometimes might be?