Task: Question Understanding
Input (English): Question: Fish, like many other water animals, require oxygen in order to survive. The water they swim in contains oxygen and hydrogen. Oxygen reaches parts of the fish's body when ___. (A) the fish drinks the water through its mouth and allows hydrogen into its body (B) water is absorbed through tiny pores in the skin and allows oxygen into the fish's body (C) water passes through the gills, which removes hydrogen from the water and allows it to enter the fish's body (D) water passes through the gills, which removes the oxygen from the water and allows it to enter the fish's body?
Output (English): oxygen, hydrogen., Oxygen, reaches, fish's, body