Select the option that expresses the given sentence in passive voice.

I am training a new batch of officers now.

A new batch of officers is being trained by me.

In the active voice sentence, "I am training a new batch of officers now," the subject (I) performs the action (am training) on the object (a new batch of officers).

To convert the sentence to passive voice, we make the object (a new batch of officers) the subject of the sentence and use the verb "is being trained" in the corresponding form. The agent or the doer of the action (me) is introduced with the preposition "by."

Therefore, the passive voice sentence is: "A new batch of officers is being trained by me."

The other options are incorrect:

1. "A new batch of officers are trained now" is in active voice, where the subject "a new batch of officers" is the doer of the action "are trained." To convert the sentence to passive voice, we need to change the verb form to "is being trained."

2. "A new batch of officers were being trained by me now" changes the tense of the sentence to past continuous tense ("were being trained") and does not match the original sentence's present tense.

3. "A new batch of officers are training me now" is in active voice and conveys a different meaning, suggesting that the officers are training the speaker. This is not a passive construction.

Therefore, the correct option is: "A new batch of officers is being trained by me."