Wisconsin CNA State Exam 2026 – 400 Free Practice Questions to Pass the Exam

White blood cells, also known as leukocytes, are a crucial component of the immune system. Their primary responsibility is to defend the body against pathogens such as bacteria, viruses, and other foreign invaders. They achieve this through various mechanisms, including the identification and destruction of harmful substances, orchestrating immune responses, and producing antibodies.

In the context of the other options, the measure of heaviness pertains to physical properties unrelated to the body's defense mechanisms. A balanced meal refers to nutrition, which, while important for overall health, does not directly involve the function of white blood cells. The description of a resident being unaware of others does not connect to the physiological functions of white blood cells in any relevant manner. Thus, option C stands out as the only choice that accurately describes the critical protective role that white blood cells play in maintaining health and combating disease.