**Core Concept**
The classification of surgical procedures into clean, clean contaminated, dirty, or contaminated is based on the potential for bacterial contamination and the risk of surgical site infection. This classification guides perioperative antibiotic prophylaxis and infection control protocols.

**Why the Correct Answer is Right**
Elective hemicolectomy for colon carcinoma involves a surgical procedure where the colon is resected, and the site is opened through the abdominal cavity. While the procedure is not performed on an infected or open wound, it involves entering the peritoneal cavity and manipulating bowel tissue, which carries a risk of introducing bacteria from the bowel lumen into the surgical field. This makes it a **clean contaminated** procedure — not sterile, but not involving direct contact with infected tissue or open drainage.

**Why Each Wrong Option is Incorrect**
Option A: Clean procedures involve only sterile sites with no risk of contamination, such as a laparoscopic cholecystectomy with no bowel involvement. Hemicolectomy involves bowel manipulation, so it is not clean.
Option C: Dirty procedures involve open wounds with active infection or direct contact with infected tissue (e.g., abdominal wall abscess). This is not the case in elective hemicolectomy.
Option D: Contaminated procedures involve direct exposure to infected tissue or drainage (e.g., open trauma or peritonitis). Hemicolectomy is not performed on infected tissue.

**Clinical Pearl / High-Yield Fact**
In elective bowel resections, the procedure is classified as **clean contaminated** because it involves the bowel but is performed in a controlled setting with no active infection — this justifies the use of **antibiotic prophylaxis** to reduce surgical site infection risk.

✓ Correct Answer: B. Clean contaminated