Final Answer:
White blood cells are the primary blood cells responsible for fighting infections. They play a crucial role in the immune system, actively engaging in the defense against pathogens and foreign substances in the body. Therefore, the correct answer is C) White blood cells.
Step-by-step explanation:
White blood cells, or leukocytes, are a diverse group of cells that form a crucial part of the immune system. They can be further classified into different types, such as neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Each type has specific functions in recognizing and neutralizing various pathogens.
Neutrophils, for example, are the most abundant white blood cells and are essential for combating bacterial infections. They engulf and destroy bacteria through a process called phagocytosis. Lymphocytes, another type of white blood cell, are central to the adaptive immune response. They include T cells and B cells, which work together to recognize and eliminate specific pathogens. Monocytes transform into macrophages, which are efficient scavengers that engulf and digest cellular debris and pathogens.
The overall white blood cell count is an important indicator of the body's immune health. It is typically measured in thousands per microliter of blood. For instance, a normal range for total white blood cell count is approximately 4,000 to 11,000 cells per microliter. Deviations from this range may indicate underlying health issues, such as infections or immune system disorders.
In conclusion, white blood cells play a pivotal role in the body's defense against infections, demonstrating the critical importance of these cells in maintaining overall health and well-being.
Therefore, the correct answer is C) White blood cells.