What percentage of lymphocytes are B cells?

• A. 45%
• B. 25%
• C. 30%
• D. 15%

Answer: (B)

Understanding the distribution of lymphocyte subsets helps you recall how the immune system is organized. Among circulating lymphocytes, T cells form the majority, while B cells are a smaller, but still significant, portion. A commonly cited figure for B cells in peripheral blood is about a quarter of lymphocytes. This is why 25% is the best fit for this question—it's a standard memory value that aligns with typical teaching and exam conventions.

The other percentages would overstate or understate B cells relative to the usual distribution. For instance, numbers near half or a sizable minority wouldn’t match the common view that B cells are not the dominant lymphocyte type. As with many biological measures, exact percentages can vary with age, health, and tissue, but 25% sits closest to the widely taught figure used in exams.