In the following question, a sentence has been given in Active/Passive voice. Out of the four alternatives suggested, select the one which best expresses the same sentence in Passive/Active voice.

Q:

Who has composed this song?

• 1
  Composing of this song has been done by who?
• 2
  This song has been composed by whom?
• 3
  This song will be composed by whom?
• 4
  Who composes this song?