Rewrite the sentence in the active voice.
The flute is being played by Shankar.

Correct option is B

The correct option is (b) Shankar is playing the flute.
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 Present Continuous Tense.
Rule: In Present Continuous Tense, the structure for changing passive to active is:
Passive voice: Object + is/am/are + being + V3 + by + Subject.
Active voice: Subject + is/am/are + V1 + ing + Object.
Corrected sentence: Shankar is playing the flute.