Select the correct passive form of the given sentence.
"The principal might be watching the surveillance footage."

Correct option is D

The correct passive voice is “The surveillance footage might be being watched by the principal.”
Explain the rules of conversion (Active → Passive) with structure in detail:
· Identify form: Modal + be + V1-ing ( might be watching) → this is a modal progressive.
· Passive structure for Modal Progressive: Modal + be + being + V3 (+ by + agent).
· Apply the rule: might be watching → might be being watched; swap subject (the principal) with object (the surveillance footage).
· Final form: The surveillance footage + might be being + watched (V3) + by the principal.
Structure:
· Active: Subject + modal (might) + be + V1-ing + Object.
· Passive: Object + modal (might) + be + being + V3 (+ by + Subject).
Example:
· Active: She may be reading the files. → Passive: The files may be being read (by her).
Why other options are incorrect:
· (a) Missing modal and progressive aspect; reduces meaning to present continuous passive.
· (b) Ungrammatical: might watched lacks be and being.
· (c) might be watched = simple modal passive (habitual/possibility), but does not carry the ongoing/progressive sense of “be watching.”
· (d) Preserves both modal and progressive → correct.