B)Abdominal surgery
Explanation:
In functional obstruction, the intestine can become adynamic from an absence of normal nerve stimulation to intestinal muscle fibers. For example, abdominal surgery can lead to paralytic ileus. Mechanical obstructions result from a narrowing of the bowel lumen with or without a space-occupying mass. A mass may include a tumor, adhesions (fibrous bands that constrict tissue), incarcerated or strangulated hernias, volvulus (kinking of a portion of intestine), intussusception (telescoping of one part of the intestine into an adjacent part), or impacted feces or barium. (less)