We would call this scientific research
Red cells take up 40%-50% of the total blood volume
Lipids are found in cell membranes in double layer which is called "Lipid-bilayer".
So, option A is your answer.
Hope this helps!
<span>When an athlete is nearing the end of a race and her cells are low on oxygen, it is likely to be fermentation. When cells have used up all their oxygen they ferment glucose into lactic acid. Fermentation is a metabolic process that consumes sugar in the absence of oxygen</span>
