Which of the following is an example of active transport? Water enters a cell through specialized channel proteins called aquaporins, causing the cell to swell. Plucose is absorbed in the gut, going from a lower to a higher concentration gradient. After meat is salted, water leaves the cells of the meat, causing them to shrivel up.

The example of active transport from the options you provided is: **Glucose is absorbed in the gut, going from a lower to a higher concentration gradient.** Active transport involves the movement of substances against their concentration gradient (from a region of lower concentration to a region of higher concentration) and typically requires energy, often in the form of ATP. In the case of glucose absorption in the gut, glucose is transported from the intestinal lumen (where its concentration is lower) into the cells lining the gut (where its concentration is higher), which is an example of active transport. The other two options describe passive processes: the movement of water through aquaporins (osmosis) and the loss of water from cells due to osmosis when meat is salted.