In terms of water potential and plant transport, how does transpiration help a plant during hot summer conditions?

• A. It increases water potential in leaves, causing water to move out of the xylem and into the atmosphere more slowly.
• B. It creates a water potential gradient (lower water potential in leaves) that pulls water upward through the xylem, helping deliver water for cooling and maintaining cell turgor.
• C. It pumps water actively into the xylem using ATP, independent of any water potential gradient.
• D. It stops water loss by closing stomata permanently, which increases carbon dioxide uptake for photosynthesis.

Answer: (B)