Which of the following steps has proven benefit in decreasing puerperal infection following cesarean section:

Ans. is c, i.e. Administration of single dose of ampicillin or 1st generation cephalosporin at the time of cesarean deliveryRef William 24/e, p 685The only proven way of decreasing uterine infection following cesarean section is administering a single dose of ampicillin or 1st generation cephalosporin at the time of cesarean delivery.Rest none of the steps like single layer closure of uterus, closure of peritoneum, use of stapler to close skin incision instead of surtures, etc. are not proven to have any benefits as far as incidence of infection is considered following surgery.