Correct option is C
The correct option is (c) I bought a few bags.
Definition of Active Voice: In active voice, the subject of the sentence performs the action.
Definition of Passive Voice: In passive voice, the subject of the sentence receives the action.
Tense identification: The sentence is in Simple Past Tense.
Rule: In Simple Past Tense, the structure for changing passive to active is:
Passive voice: Object + was/were + V3 + by + Subject.
Active voice: Subject + V2 + Object.
Corrected sentence: I bought a few bags.