Question

lo 2.1. what is the main function of red blood cells?
to store excess nutrients.
to regulate blood pressure.
to transport oxygen from the lungs to the different parts of the body.
to protect the body from infection.
to remove carbon dioxide from the body.

Explanation:

Red blood cells contain hemoglobin, which binds to oxygen in the lungs. They then transport this oxygen to various tissues and organs in the body. Storing nutrients is not their function (that's more for organs like the liver). Regulating blood pressure is mainly done by the cardiovascular system's overall function (e.g., blood vessel constriction/dilation). Protecting from infection is the role of white blood cells (e.g., lymphocytes, neutrophils). Removing carbon dioxide is a function related to the respiratory system's gas exchange process, but red blood cells do carry some carbon dioxide (in a minor way compared to oxygen transport), but their main function is oxygen transport.

Answer:

To transport oxygen from the lungs to the different parts of the body.