What is the normal range for WBC in a CBC?

What is the normal range for WBC in a CBC?

• A. 4,000-10,000/mm³
• B. 4,000-12,000/mm³
• C. 5,000-12,000/mm³
• D. 4,500-11,000/mm³

Answer: (D)

The main idea here is knowing the typical reference range for white blood cell count in a CBC. For adults, a common normal range is about 4,500 to 11,000 cells per microliter (mm3), which is also written as 4.5–11.0 x10^9/L in SI units. This range accounts for normal physiological variation between individuals and slight differences among laboratories. The option that uses 4,500–11,000/mm³ matches this widely accepted reference window, making it the best fit. Other ranges either lower the lower limit or raise the upper limit, which don’t align with the standard adult reference values commonly used in practice.

The main idea here is knowing the typical reference range for white blood cell count in a CBC. For adults, a common normal range is about 4,500 to 11,000 cells per microliter (mm3), which is also written as 4.5–11.0 x10^9/L in SI units. This range accounts for normal physiological variation between individuals and slight differences among laboratories.

The option that uses 4,500–11,000/mm³ matches this widely accepted reference window, making it the best fit. Other ranges either lower the lower limit or raise the upper limit, which don’t align with the standard adult reference values commonly used in practice.