Select the option that expresses the given sentence in passive voice:
They have built a new bridge across the river.

Correct option is A

The correct passive voice is (a) A new bridge has been built across the river by them.
Rules for conversion:
· Identify the object ("a new bridge") and make it the subject.
· Convert the tense: "have built" changes to "has been built."
· Retain the agent ("by them").
· Structure:
· Active voice: Subject + have/has + V3 + object.
· Passive voice: Object + have/has + been + V3 + by + subject.
Example: She has written a book. → A book has been written by her.