Correct Answer:
B. had rung
This question tests the correct structure for the idiomatic expression "No sooner... than." This phrase is used to indicate that one event happened immediately after another. When "No sooner" begins a sentence, it requires inversion, meaning the auxiliary verb comes before the subject. The tense used with "No sooner" is typically the past perfect, as it describes the first of two sequential past actions.
- B: had rung is the correct answer. The structure is "No sooner + had + subject + past participle + than + subject + past simple." Here, "had" is the auxiliary verb, and "rung" is the past participle of "ring." So, "No sooner had the bell rung than the students rushed out" correctly follows this pattern.
- A: did ring is incorrect. While "did" is an auxiliary for inversion, it would be used with the past simple (e.g., "No sooner did the bell ring..."), which is less common and less formal than the past perfect construction with "No sooner."
- C: rung is incorrect. "Rung" is the past participle, but it is missing the necessary auxiliary verb "had" to form the past perfect tense and facilitate inversion.
- D: rings is incorrect. This is the present simple tense, which is inappropriate for describing two sequential past actions.