Answer:
a, b and c are false statements.
Step-by-step explanation:
a. The malarial pathogen causes a more dangerous disease in people who carry the gene for sickle cell anemia. (Actually people who carry the sickle cell trait have a biological advantage of protection against malaria.The sickle cell collapse when Plasmodium tries to hook)
b. Malaria causes sickle cell anemia, making this trait more common in people who live where malarial parasites thrive. (Sickle cell anemia can only be caused by genetic factors)
c. There is an increased occurrence of the sickle cell gene in populations where malaria is common. (This is also wrong because sickle cell trait can’t be developed by environmental factor.It requires some extent of genetic defect)