A. Hemorrhage: This complication involves acute, profuse blood loss from damaged vascular structures within the surgical site. Clinical manifestations typically include hematoma formation, hypovolemia, or bright red sanguineous output. The presence of intact edges and serosanguinous fluid contradicts active arterial or venous bleeding. B. Wound infection: Pathogenic colonization triggers an inflammatory response characterized by localized erythema and edema around the incision. Increased serosanguinous or purulent exudate reflects the body's immunological reaction to microbial invasion. These clinical markers are classic precursors to localized sepsis or abscess formation. C. Wound dehiscence: This mechanical failure involves the partial or total separation of previously approximated wound layers. While serosanguinous drainage can precede this event, the question specifically states the incision edges remain intact. Therefore, the structural integrity of the wound has not yet been compromised. D. Fistula development: This represents the formation of an abnormal passage between two internal organs or an organ and the skin. It usually results from chronic inflammation, malignancy, or severe infection rather than acute post-operative edema. The localized symptoms described are more indicative of a superficial or deep infection.