Which of the following is reabsorbed in the jejunum?

The jejunum is the middle section of the small intestine and plays a crucial role in the absorption of nutrients from digested food. Among the options presented, folate is primarily absorbed in the jejunum. Folate, also known as vitamin B9, is a water-soluble vitamin that is essential for DNA synthesis and repair, as well as for cell division and growth.

The jejunum is particularly well adapted for the absorption of water-soluble vitamins like folate due to its extensive surface area provided by villi and microvilli, which increase efficiency in nutrient uptake. While some iron can be absorbed in the jejunum, its primary absorption occurs in the duodenum, the first part of the small intestine. Vitamin B12, on the other hand, is mainly absorbed in the ileum, the final section of the small intestine. Although water is absorbed in the jejunum, it is also widely absorbed throughout the entire intestines, so it is not exclusive to this segment.

Thus, the correct answer identifies folate as the nutrient specifically absorbed in the jejunum, highlighting the importance of this segment in the digestive process.