Correct Answer & Explanation
Option A
• This is a conditional sentence (Type 1), which expresses a real and possible situation in the future.
• In Type 1 conditional sentences, the 'if' clause (condition) uses the Simple Present Tense, and the main clause (result) uses the Simple Future Tense.
• The main clause 'we will stay at home' is in the Simple Future Tense.
• Therefore, the 'if' clause must be in the Simple Present Tense.
• 'It' is a third-person singular subject, so 'rains' is the correct form.