Select the option that expresses the given sentence in active voice.
Your homework must be completed before the deadline.

Correct option is C

Active Voice: In Active voice the subject is the one doing the action.
Passive Voice: In Passive voice the subject is the recipient of the action.
To convert active voice into passive voice the object becomes the subject and the subject becomes the object.
For Simple Future Tense as given in the question the structure for changing tense into active to passive and vice versa is
Subject + modal+ v1+ object. (Active voice)
Object+ modal+ be +V3+ by + subject. (Passive voice)