Select the option that expresses the given sentence in passive voice.
The government is implementing new policies to reduce pollution in the city.

Correct option is D

The correct passive voice expression is (d) "New policies are being implemented by the government to reduce pollution in the city."
The active sentence has "is implementing," which is a present continuous form. The corresponding passive form should maintain the same tense, which is correctly done in option (d) where the action is ongoing.
Grammatical rule used: In passive voice constructions, the object of the active sentence becomes the subject of the passive sentence, and the verb form changes to include the appropriate form of 'be' and the past participle of the main verb.
Conversion rule:
Present continuous
Subject + is, am, are + verb + ing + object -> <- Object + auxiliary verb (is, am, are) + being + past participle + by + subject.