Explanation
Correct Answer: (c) A letter was written by her
Detailed Explanation
The given sentence is in the Active Voice and uses the Simple Past Tense:
Active Voice Structure: Subject + V2 (wrote) + Object
To convert a Simple Past Tense sentence into the Passive Voice, we follow this specific structural formula:
Passive Voice Structure: Object + was/were + V3 (Past Participle) + by + Subject
Let's break down the transformation step-by-step:
Object becomes Subject: "A letter" (Singular)
Helping Verb: Since "A letter" is singular and the tense is simple past, we use was.
Main Verb in V3 form: The past participle form of 'write' (write → wrote → written) is used.
Subject becomes Agent: The pronoun "She" changes to its objective form, her, introduced by the preposition "by".
Combining these elements gives us: "A letter was written by her."