Which sentence is in active voice? A The boy was brought to the nurse's office. B The boy was told to wait for the nurse. C The principal saw the boy pulling on his loose tooth. D The loose tooth was pulled out.

A. The boy was brought to the nurse's office.

Explanation: Active voice in grammar is when the structure follows or is written as a subject, verb and object form or structure where the subject is performing or doing the action described by the verb. The active voice makes it easier to read sentences and makes write ups clear and easy to understand.