Explanation
Correct Answer: (c) had he
Complete Sentence:
Hardly had he finished the work when the bell rang.
Detailed Explanation
This question is based on the grammatical concept of Adverbial Inversion (specifically using negative or restrictive adverbs at the beginning of a sentence).
Rule of Inversion: When a sentence begins with a negative adverb or adverbial phrase like Hardly, Scarcely, No sooner, or Barely, the standard subject-verb order is inverted. This means the auxiliary verb (helping verb) must come before the subject.
Structure: Hardly+Auxiliary Verb+Subject+Main Verb (V3)+⋯+when+…
Tense Consistency: The second part of the sentence uses the simple past tense ("the bell rang"). To show an action that was completed just before another past action, we must use the Past Perfect Tense in the first clause.
Past Perfect Inversion Structure: Hardly+had+subject+past participle (V3)
