For fire safety, there should be no heating/cooling returns in
a)garages
b)bedrooms
c)dining rooms
d)ceilings

Thanks for posting your homework. It's multiple choice. Pick a choice and ask questions about it to yourself. Like:

Why would I not want a return in the ceiling? Have I seen them there before?
Is it hot up there? Cool up there? Is this the BEST answer?

Try

Segarag

A is the obvious choice

I would think you could look up the answer much faster than posting and waiting for an answer here.

Got it - thanks

Now, since you got it, can you tell us why?