Select the option that expresses the given sentence in active voice.
The experiment is being completed by the whole class.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. The whole class is completing the experiment.
The given sentence is in passive voice:
The experiment (subject) is being completed (passive present continuous) by the whole class (agent).
To change into active voice, the doer (the whole class) becomes the subject, and the receiver (the experiment) becomes the object.
The tense 'is being completed' is present continuous passive, so the active form will be present continuous active → 'is completing'.
Therefore: The whole class is completing the experiment.
Why others are incorrect:
'has been completing' – Present perfect continuous tense, not matching the original tense.
'has completed' – Present perfect tense, changes the time meaning.
'completes' – Present simple tense, not the same as present continuous.