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

Shiva wrote a letter to the head of the HR Department in response to the advertisement.

A letter was written by Shiva to the head of the HR department in response to the advertisement.

The correct passive form of the given sentence is A letter was written by Shiva to the head of the HR department in response to the advertisement.

The active voice of the sentence is Shiva wrote a letter to the head of the HR Department in response to the advertisement. This sentence is in the simple past tense, which is used to describe an action that happened in the past. 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 "Shiva" and the main verb is "write." The past participle of "write" is "written." So, the passive form of the sentence is A letter was written by Shiva to the head of the HR department in response to the advertisement.

The other options are incorrect because:

• A letter had been written by Shiva to the head of the HR department in response to the advertisement. is in the past perfect tense, which is used to describe an action that happened in the past before another action happened. There is no other action mentioned in the sentence, so the past perfect tense is not appropriate.
• A letter was written by the head of the HR department to Shiva in response to the advertisement. is the active voice of the sentence, but the subject of the sentence is incorrect. The letter was written by Shiva, not the head of the HR department.
• A letter was wrote by Shiva to the head of the HR department in response to the advertisement. is grammatically incorrect. The verb "to write" needs to be in the past participle form, which is "written."