Which sentence is written in passive voice?

• A. The cat chased the mouse.
• B. The teacher explains the lesson.
• C. The chef cooked the soup.
• D. The mouse was chased by the cat.

Answer: (D)

Passive voice happens when the focus is on the receiver of the action rather than who is doing the action, so the recipient becomes the subject and the doer appears in a by-phrase or is omitted. The sentence that fits this pattern is the one where the mouse is the subject and the cat is named after by, as in “The mouse was chased by the cat.” Here, the action of chasing is done to the mouse, and the cat is the one who performed it, which is why this sentence is passive. The other sentences place the doer at the front and show the action directly, like “The cat chased the mouse,” “The teacher explains the lesson,” and “The chef cooked the soup.” They are all active voice, where the subject does the action upfront.