Which of the following sentences is in passive voice?

The sentence identified is in passive voice because it emphasizes the action being performed on the subject rather than who is performing the action. In this case, "The book was read by the entire class" indicates that the book received the action of being read, while the doer of the action (the entire class) is mentioned afterward. This construction focuses on the action happening to the subject (the book) rather than how the subject is performing the action, which defines passive voice.

In contrast, the other sentences are in active voice, where the subjects perform the actions directly. For instance, "The chef cooked a delicious meal" presents the chef as the doer of the action, highlighting what he did rather than the meal itself. Understanding the difference between active and passive voice is crucial in identifying the structure and focus of a sentence.