Convert the following sentence in Passive Voice by choosing the appropriate answer from the given list.

The soldiers promptly obeyed his command.

The command was promptly obeyed by the soldiers.

The correct answer is Option (2) - The command was promptly obeyed by the soldiers.

To convert a sentence from Active Voice to Passive Voice, follow these steps:

1. Identify the object (his command) in the active sentence and make it the subject in the passive sentence.
2. Use the correct tense of the verb "to be" along with the past participle of the main verb (was obeyed).
3. Include the agent (by the soldiers) if necessary. So, The command was promptly obeyed by the soldiers. is the right answer.
4. "The command should be obeyed might now, soldiers.": Grammatically incorrect and changes the meaning.
5. "Obey the command promptly soldiers!": Not in passive voice; this is a command in active voice.
6. "The command is promptly obeyed by the soldiers.": Incorrect tense; "is obeyed" indicates present tense, while the original sentence is in past tense.