In the human body, the appendix is attached to the large intestine, specifically to the cecum. Option 1, "The large intestine," is the correct answer.

The appendix is a small, finger-shaped organ located in the lower right area of the abdomen. It is connected to the cecum, which is the first part of the large intestine or colon. The cecum is a pouch-like structure that forms the junction between the small intestine and the large intestine.

The appendix itself does not have a well-defined function in humans. It is considered a vestigial organ, meaning it has lost or reduced its original function throughout evolution. In some animals, like herbivores, the appendix is involved in the digestion of cellulose-rich diets. However, in humans, it is generally believed to have a minimal role in digestion, if any.

Despite its minimal role in digestion, the appendix can sometimes become inflamed or infected, leading to a condition known as appendicitis. Appendicitis is a medical emergency that typically requires surgical removal of the appendix (appendectomy) to prevent complications. This removal does not significantly affect the overall functioning of the digestive system.

To summarize, the appendix is attached to the large intestine, specifically to the cecum, which is the first part of the large intestine or colon.