In passive voice sentences, the subject is acted upon, or receives the action. The original agent of the action is often de-emphasized or omitted. * **Core Concept:** Understanding the structure of passive voice sentences. * **Solution Analysis:** Passive voice focus on the receiver of the action. * **Detailed Option Analysis:** * **A:** Incorrect. Agent is the doer, not the subject in passive voice. * **B:** Correct. The subject receives the action in passive voice. * **C:** Incorrect. The instrument is a tool, not the subject. * **D:** Incorrect. Modifier is an adjective or adverb not the subject * **Common Mistakes:** Confusing active and passive voice.