Note that this is not the past subjunctive of ser "fuera", but the adverb "fuera" which means "(out)side".
- Ella está fuera de la casa (she is outside the house)
Wrong. if we're practicing the past subjunctive, (a) what's this question doing in here formulated as such (looking for ¡Fuera! as an answer) and (b), why aren't they fishing for an answer that might require something closer to what was covered in the module?