10. Many trees in temperate environments have broad, flat leaves. How does this leaf structure support the function of obtaining energy? a. A flatter surface allows more oxygen to enter the leaf b. A flatter surface allows more water to be retained in the leaf during periods of dryness. A larger surface area allows more light to reach the mesophyll where photosynthetic cells are locate d. A larger surface area allows more room for photosynthetic cells:​