The correct option is A If both the assertion and the reason are true and the reason is a correct explanation of the assertion
In caduceus, leaves fall down soon after their appearance, e.g., Opuntia. In deciduous almost all leaves fall off almost Simultaneously at the end of growing season. The phenomenon is called leaf fall, e.g., Mulberry, Poplar. In Euphorbia Tyrolean the leaves are drought deciduous.