Final answer:
Hemorrhoids are caused by varicose veins in the perianal region, which result from faulty valves in the veins, leading to blood pooling and vein bulging. The correct answer is option: b. Varicose veins in perianal region.
Step-by-step explanation:
Hemorrhoids occur due to varicose veins in the perianal region. This condition arises when the veins become enlarged and twisted because their valves have become ineffective. As a result, blood pools in these veins, causing them to stretch and bulge.
Hemorrhoids are often associated with factors that increase pressure in the lower rectum, such as straining during bowel movements, chronic constipation, pregnancy, or standing for long periods.
Effective management can include dietary changes to increase fiber intake, using support hose, and in some cases, surgery may be required to alleviate severe cases.