Answer :
B. la terraza means terrace. That is where you would find a barbecue.
Answer: option B, La terraza.
Explanation: Let's analyze the options:
A "el dormitorio" means "the bedroom", this is not a nice place to do a barbeque, so we can discard this option.
B "La terraza" this means "the terrace", this is a good place, because the smoke can flow.
C "el atico" this means "the penthouse", this also is a bad place because you will fill the penthouse with smoke.
D "el sotano", means "the basement", this has the same problem as before.
So the only option tath makes sense, is the option B, La terraza.