Unlike blood capillaries, lymphatic capillaries:

A. Plasma refers to the liquid component of blood, not tissue fluid.
B. Chyle is a specific type of lymph that is rich in fats, typically absorbed from the intestines, and not the general fluid that enters the lymphatic vessels.
C. Lymph is the correct answer. It is the fluid that forms when tissue fluid enters the lymphatic vessels. Lymph is derived from interstitial fluid and contains water, proteins, waste products, and immune cells.
D. Serum is the liquid portion of blood without clotting factors, but it is not related to the lymphatic system.

A. The spleen does not shrink after puberty. It remains an active part of the immune and blood filtration systems throughout life.
B. The thymus (note: it appears misspelled as "Thygus" in the question) is the correct answer. It plays a crucial role in the development of T lymphocytes (T cells) during childhood but begins to shrink and become replaced by fatty tissue after puberty—a process known as involution.
C. The liver does not shrink after puberty. In fact, it continues to grow and function in metabolism, detoxification, and digestion throughout a person’s life.
D. The cisterna chyli is a dilated sac at the lower end of the thoracic duct involved in lymphatic drainage. It does not shrink after puberty and remains functional throughout life.