The small intestine is longest and narrow tubular part of the alimentary canal. Small intestines have three parts- Duodenum, Jejunum and ileum. The duodenum is short (20 to 25 centimeters long) and wider anterior part into which stomach empties. The jejunum is coiled middle part which is 0.8 to 1.5 meters in length while ileum is the longest terminal part with 3 to 3.5 meters in length. Thus, the correct answer is option B.