Ans. is b i.e. Use of blood transfusion Friends, let's discuss each option one by one. Urinary catheterization (Option 'a) It is very obvious that urinary catheterization for > 7 days will increase the chances of post operative infection. "Almost all nosocomial UT/ are associated with preceeding instrumentation and indwelling catheter, which create a 3-10% risk of infection each day." Surgery for malignancy (Option 'c) Telinde's Operative Gynaecology 9/e, p 197 and William Gynae, l/e p 77 gives a list of risk factors for Post Operative Infection. Risk factors for Postoperative Infection : Altered immunocompetence Obesity Bacterial vaginosis Excessive intraoperative blood loss Telinde's Operative Gynaecology Radical surgery - a/w prolonged surgical procedure (>3-5 hrs) Prolonged preoperative hospitalization Operative inexperience * Lower socioeconomic status * Poor nutrition * Excessive devitalized tissue * Diabetes mellitus * Failure to use prophylactic anitbiotics * Surgery in an infected operative site. Young age/old age (Williams Gynae 1/e, p 77) From the table it is clear : Radical surgery which is carried out for carcinoma endometrium and carcinoma cervix carries risk for postoperative infection. (Option "c") As far as age is concerned : Telinde operative gynaecology 9/e. p 196 says: "Young age has been considered a risk factor for vaginal posthysterectomy infection, although the exact reason is unclear." And table in Williams Gynae lie. p 77 gives old age as a risk factors for abdominal hysterectomy and young age as a risk factor for vaginal hysterectomy. This leaves us with option 'b' i.e. use of blood transfusion. Though theoretically by blood transfusion risk of infection with - HIV. hepatitis B/C, G etc is high but practically the technique by which blood is prepared there is minimal risk .