Question

multiple choice question
what is the main function of red blood cells?
transport carbon dioxide from the lungs to the tissues
transport both oxygen and carbon dioxide
transport oxygen from the tissues to the lungs

Explanation:

Red blood cells contain hemoglobin which binds to oxygen in the lungs and releases it to the tissues. They also carry some carbon - dioxide from tissues back to the lungs, but their main function is oxygen transport.

Answer:

Transport both oxygen and carbon dioxide