People with at Least One Copy of the HLA-B53 Gene

Multiple Choice

People with at least one copy of the HLA-B53 gene are better able to beat back malarial infections before the infection progresses. If this is a coevolutionary arms race between Plasmodium and humans, what would the next step in this race be?

A) to see humans with more than one copy of the HLA-B53 gene
B) to see humans without the HLA-B53 gene
C) to see Plasmodium populations that counter the HLA-B53 gene
D) to see Plasmodium populations that have the HLA-B53 gene
E) to see a mutation in the HLA-B53 gene that makes it more effective against malarial infections