Which arrangement lists the segments that comprise the small intestine?

• A. Duodenum, Jejunum, Cecum
• B. Jejunum, Ileum, Colon
• C. Esophagus, Stomach, Duodenum
• D. Duodenum, Jejunum, Ileum

Answer: (D)

The sequence of sections of the small intestine from the stomach onward is duodenum, then jejunum, then ileum. The duodenum is the first section where chyme mixes with bile and pancreatic juice to kick off digestion. The jejunum is the middle part where most nutrients are absorbed, thanks to a highly folded inner lining that increases surface area. The ileum is the last portion, continuing absorption (including bile acids and vitamin B12) and passing contents into the large intestine. The other options mix in parts of the large intestine, like the cecum and colon, or include non-small-intestine sections such as the esophagus or stomach, so they don’t reflect the correct order of the small intestine’s segments.