The lymphatic system contributes to immunity by:

Correct Answer: B

Rationale: It transports lymphocytes for immunity; oxygen is blood, digestion is macrophages, glucose is liver.

Correct Answer: C

Rationale: Lymph nodes trap pathogens; spleen filters blood, thymus matures T cells, appendix is minor.

Correct Answer: A

Rationale: The marginal zone separates red and white pulp; others (B, C, D) are unrelated.

Correct Answer: C

Rationale: Neutrophils are granulocytes; lymphocytes and dendritic cells are agranulocytes, monocytes become macrophages.

Correct Answer: C

Rationale: Lymphocytes are agranulocytes; neutrophils , eosinophils , and basophils are granulocytes.