Correct Response: C. Stomata are openings found primarily on the underside of a plant's leaves and on its stem. When the stomata close, water vapor in the plant cannot escape, thus reducing the rate of water loss. Pressure in the root (A) affects the amount of nutrients, including water, absorbed by the root from the environment, but root pressure is not affected immediately with the closure of the stomata. Transportation of nutrients (B) throughout the plant uses special tissues; the closing of the stomata, however, does not affect the immediate movement of nutrients. A plant increases its frost resistance (D) by changing the colloidal consistency of its protoplasm (or in the case of woody plants, its sap), but the closing of the stomata does not trigger or affect the frost resistance of the plant.
