a. She got up when the alarm clock went off.
b. We visited Spain three times last year.
Choose the correct sentence from the options given above.

The correct answer is Option D (Both the sentences are correct).

Key Points:
• Sentence a: 'She got up when the alarm clock went off.' Both clauses properly use simple past for simultaneous/immediate sequence in the past ('got up' and phrasal verb 'went off' = rang).
• Sentence b: 'We visited Spain three times last year.' The past time adverbial 'last year' requires simple past 'visited', which is correctly used.
• Option 4 (Both the sentences are correct).
• Both sentences are grammatically and syntactically flawless.
• Key Takeaway: Both sentences correctly use the simple past tense for completed past occurrences.