In the following question, a sentence has been given in Active/Passive Voice. Out of the four/five alternatives suggested, select the one which best expresses the same sentence in Passive/Active Voice. They have built a perfect dam across the river.

• A. A perfect dam should have been built by them.
• B. Across the river was a perfect dam.
• C. Across the river a perfect dam was built.
• D. A perfect dam has been built by them across the river.

Answer: (D)