Which one is correct? (Subject-verb agreement)

I'd think of this as being analogous to saying "what materials are the drawer and cabinet made of?"

This would make this phrase the more correct of the two phrases: "What are the drawer and the cabinet made of?"

In this case, the drawer and cabinet might be made of more than one (different) materials.

Sometimes the dumb grammar checker in MS Word is totally wrong.

Thanks, Mr. Ragman!