The Endosymbiotic Theory states the mitochondria and the chloroplasts were once free-living prokaryotic cells. Considering the size of each, why does this make sense?

answer: although many types of viruses can cause a common cold, rhinoviruses are the most common culprit. a cold virus enters your body through your mouth, eyes or nose. the virus can spread through droplets in the air when someone who is sick coughs, sneezes or talks. theres your answer

explanation:

i think the answer is b.

i thinking chemical change