Correct Answer: Passive construction is not possible.

Solution : The correct choice is the fourth option .

Passive voice is the voice in which the object experiences an action rather than the person who performs the action. Hence, the object in the active sentence becomes the subject in the passive voice.

The verb smells in this context is a linking verb describing the state of the subject (the sewage water), and such sentences typically don't have a direct passive equivalent. The structure cannot be effectively converted into a passive structure while maintaining the original meaning and grammatical correctness.