Find out the correct option for the given sentence.

Concept

A correctly constructed sentence joins related ideas with proper coordination or subordination, keeps modifiers next to what they describe, and avoids comma splices (two independent clauses wrongly joined by only a comma). Each clause must read as a complete, logically ordered thought.

Application

Here two events are being reported: rain that fell continuously, and a town left flooded. A clean sentence links these two independent clauses with the conjunction and, and places the idiom at a stretch (meaning "continuously, without a break") right after the duration it modifies. The version "It rained for five hours at a stretch and the town was under knee-deep water." does exactly this: two complete clauses, correctly coordinated, with every modifier in place.

Why the others fail

• "At a stretch, it rained for five hours, under knee-deep water, the town was" — trails off into an incomplete clause ("the town was" has no completion) and strings fragments together with commas.

• "Under knee-deep water, the town was, at a stretch it rained for five hours." — the clauses are jammed together with a stray comma and "at a stretch" is dropped in the wrong place, breaking the flow.

• "The town was, at a stretch, under knee-deep water, it rained for five hours." — "at a stretch" is wedged where it modifies nothing sensible, and the two ideas are spliced with a comma instead of a proper conjunction.