Deciduous means 'the dropping of a part that is no longer needed' or 'falling away after its purpose is finished'. Most deciduous trees have broad leaves that are susceptible to being damaged during cold or dry weather. In contrast, most evergreen trees either live in warm, wet climates or they have weather-resistant needles for leaves. However, there are exceptions in nature, such as tamarack trees, that shed their needles every autumn and live oaks that retain their broad leaves for the entire year even in relatively cool climates. It will help in reducing the water loss from plants. Shedding leaves help trees to conserve water and energy. As unfavourable weather approaches, hormones in the trees trigger the process of abscission, whereby the leaves are actively cut-off the tree by specialized cells. Therefore, the correct answer is option D.