Question

lo 2.5. what is the primary function of white blood cells?
protect the body against infectious diseases and foreign invaders.
transport oxygen and nutrients throughout the body.
produce hormones and control body functions.
transport oxygen throughout the body.
store and release energy when needed.

Explanation:

White blood cells, also known as leukocytes, are a crucial part of the immune system. Their main role is to defend the body against pathogens (such as bacteria, viruses, fungi) and foreign substances. They can identify, attack, and eliminate these invaders. For example, some white blood cells (like phagocytes) engulf and destroy pathogens. The option "Transport oxygen and nutrients throughout the body" is more related to red blood cells (for oxygen - mainly through hemoglobin) and plasma (for some nutrients). The option "Produce hormones and control body functions" is the role of endocrine glands. "Transport oxygen throughout the body" is specifically a red - blood - cell function. "Store and release energy when needed" is more associated with cells like muscle cells (glycogen storage) or adipose cells (fat storage).

Answer:

Protect the body against infectious diseases and foreign invaders.