Which sentence below represents an active sentence?

The test was studied for by the student.
The student studied for the test.
The test was created for the students by the instructor.

Respuesta :

"The student studied for the test." is the active sentence because it begins by describing the subject, followed by what they did.
The student studied for the test. It is active because "who is doing to action" comes first and does not use the word "by".