Answer:
Osmosis occurs where the movement of water move from a region of high water potential to a region of low water potential.
The water potential in blood capillaries need to be higher than the water content in intestinal so that the water will move from blood to intestine which cause diarrhea.
Solutions that have more H+ ions are acids.
The answer that fits the blank provided above is STEROIDS. Steroids are fat-soluble signal molecules. This is one of the derivative compounds of cholesterol along with Vitamin D and bile salts. All steroid hormones are considered as a derivative of cholesterol. The answer for this would be option D.