Change the following sentence into the Active form.
The message could have been sent by an automated system.
Show answer & explanation
Correct answer: A
Explanation
The original sentence, "The message could have been sent by an automated system," is in the passive voice. The subject ("The message") receives the action, and the doer ("an automated system") is indicated by the word "by".
To change it to the active voice, the doer becomes the subject: "An automated system". The verb phrase "could have been sent" changes to "could have sent". The original subject becomes the object: "the message".
Option A correctly follows this structure.