Which of the following sentences correctly uses an inverted conditional structure to express a hypothetical situation without the word 'if'?
✓ Correct Answer: Option A
Option A correctly uses an inverted conditional for a past hypothetical situation (third conditional): 'Had + subject + past participle'. Option B uses inversion for a future/present hypothetical ('Should + subject + base verb'). Option C mixes tenses incorrectly. Option D is a standard 'if' clause.