I guess that is:
Within the capillaries of the lungs, gases are exchanged by diffusion; O2 diffuses from the alveolus to the bloodstream and CO2 diffuses from the bloodstream to the alveolus.
It’s b because its shown in the question read it again ,and you’ll see
Plate tectonics located in our crust crashing or colliding into each other cause earthquakes to occur.
Each one is made of one original strand and one new strand.<span>It bonds together the nucleotides in the new strand</span>
