Select the correct passive form of the given sentence.
Dr. Verma advised patients to try out a new medicine for migraine.
1
The patients were being advised to try out a new medicine for migraine by Dr. Verma.
2
The old patients had been advised to try out a new medicine for migraine by Dr. Verma.
3
Patients were advised to try out a new medicine for migraine by Dr. Verma.
4
Patients have been advised to try out a new medicine for migraine by Dr. Verma.