Which type of blood cell is known for its ability to change in response to infection?

The correct choice, white blood cells, play a crucial role in the body's immune response. Unlike red blood cells, which primarily function to transport oxygen throughout the body, white blood cells are specifically designed to identify and combat infections and foreign invaders. They can change in number and type based on the body's needs during an infection. This adaptability allows them to respond efficiently to various pathogens such as bacteria and viruses.

For example, during an infection, the body may produce more types of white blood cells, such as neutrophils or lymphocytes, to effectively target and eliminate the threat. Some white blood cells can also create antibodies to remember specific pathogens, providing long-term immunity against future infections. Their dynamic response to infection underscores their vital role in maintaining health and defense against disease.

The other options do not possess this characteristic adaptive response to infections. Red blood cells are primarily involved in gas exchange, blood platelets are essential for clotting rather than immune response, and plasma cells, which are a type of white blood cell, specifically produce antibodies but are not the main modulators of the initial immune response to infection.