Which statement best explains the relationship between HbS allele frequency and malaria endemicity in Africa?
A
When an area is holoendemic, the HbS allele frequency is between 0 point 5 2 and 4 point 0 4 .B
When an area is holoendemic, the HbS allele frequency is between 0 and 0 point 5 1 .C
When an area is malaria free, the HbS allele frequency is between 0 and 4 point 0 4 .D
When an area is malaria free, the HbS allele frequency is between 12 point 6 4 and 18 point 1 8 .