Where do T-lymphocytes and B-lymphocytes mature?

The correct answer is (1) T-lymphocytes mature in the thymus, while B-lymphocytes mature in the bone marrow.

Bone marrow: The bone marrow is the soft tissue found inside the bones. It serves as the primary site of production and maturation for B cells and some types of T cells. In the bone marrow, B cells undergo differentiation and maturation, acquiring antigen receptors and becoming competent to recognize specific antigens.

Thymus: The thymus is a specialized lobed organ located near the heart and beneath the breastbone. It plays a crucial role in the maturation of T cells. Immature T cells, which are produced in the bone marrow, migrate to the thymus for further development and education. In the thymus, T cells undergo a series of maturation stages.