Statement I: Once lymphocytes have matured, they relocate to secondary lymphoid organs such as the spleen, lymph nodes, tonsils, Peyer's patches of the small intestine, and appendix.

Statement II: Secondary lymphoid organs serve as the sites where lymphocytes interact with antigens, leading to their proliferation and differentiation into effector cells.

Both statement I and statement II are correct.

The correct answer is Option (3) -Both statement I and statement II are correct.

Statement I: After lymphocytes have undergone maturation, they relocate to secondary lymphoid organs such as the spleen, lymph nodes, tonsils, Peyer's patches of the small intestine, and appendix. This migration allows the lymphocytes to be strategically positioned throughout the body where they can encounter antigens and initiate immune responses.

Statement II: Secondary lymphoid organs play a crucial role in the immune response by providing the sites where lymphocytes interact with antigens. Upon encountering antigens, lymphocytes within these organs undergo activation and proliferation. This process leads to the generation of effector cells, which are specialized immune cells that carry out various functions to eliminate the antigens and control the infection.

In summary, statement I highlights the migration of mature lymphocytes to secondary lymphoid organs, while statement II emphasizes the importance of these organs in facilitating the interaction between lymphocytes and antigens, ultimately resulting in the generation of effector cells and the initiation of an immune response.