Sickle cell trait is apparently an adaptation for the prevention of Malaria. Sickle cell trait is a condition in which the red blood cells are abnormally shaped, if they inherit two faulty copies of the gene for the oxygen-carrying protein hemoglobin. The faulty gene persists because even carrying one copy of it confers some resistance to malaria. As a result, the frequencies of sickle cell carriers are high in malaria endemic areas.
The answer is A, because the 'filling' is the jelly like cytoplasm and the edge is the cell wall