Which of the following drug is safe during pregnancy is:

(Ampicilline): Ref 37-H (700-KDT 6th) Intrauterine amniotic infection is most often caused by E. coli and group B streptococcus. In high risk patients at term or in proterm patients routine intrapartum prophylaxis of group B streptococcus (GBS) disease is recommended Penicillin G and Ampicillin are the drug of choice. Given at 1 hour before surgery Initially it was given with induction of anesthesia.But as per new protocol it is given 1 hour before surgery.For prolonged surgery it's repeated after 4 hours