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. The watchman switched on the lights before it began to grow dark.

• A. The lights were only switched on before it began to grow dark.
• B. The lights were switched on by the watchman before it began to grow dark.
• C. The lights are being switched on before it began to grow dark.
• D. The lights were being switched on by the watchman before it began to grow dark.

Answer: (B)