Select the correct passive form of the given sentence.

The Railway has started special trains for the workers.

Special trains have been started for the workers by the Railway.

The correct passive form of the given sentence is Special trains have been started for the workers by the Railway.

The active voice of the sentence is The Railway has started special trains for the workers. This sentence is in the present tense, which is used to describe an action that is happening now or that is happening repeatedly. The passive voice of the sentence is formed by putting the subject of the active sentence after the verb "to be" and the past participle of the main verb. In this case, the subject of the active sentence is "the Railway" and the main verb is "start." The past participle of "start" is "started." So, the passive form of the sentence is Special trains have been started for the workers by the Railway.

The other options are incorrect because:

• Special trains has been started for the workers by the Railway. is grammatically incorrect. The subject of the sentence is "Special trains," but the verb "has been started" is followed by the singular pronoun "has."
• Special trains will be started for the workers by the Railway. is in the future tense, while the original sentence is in the present tense.
• Special trains are being started for the workers by the Railway. is in the present progressive tense, while the original sentence implies that the starting of special trains is a completed action.