The answer should be
B Both anabolic and catabolic reactions took place in the seed and tree when it was young and growing and both continue now even though the tree reached a stable mass.
The trees should be capable to do both anabolic and catabolic reaction when it is seed or when it is already a big tree. Anabolic reaction happens when the plant making bigger molecule from many smaller molecule, such as in photosynthesis. Anabolic reaction could increase the mass of the plants or be used to make food. Catabolism reaction used to extract energy from the food.
Capillaries have thin walls, only one cell thick, that allow them to effectively perform their function.
Oh.... very nice! Yes seeing is nice