In the Section "Investigating Life: in (Extremely)Cold Blood",what Mutations Occurred

In the section "Investigating Life: In (Extremely) Cold Blood",what mutations occurred in ice fish that prevent production of hemoglobin?

A) fragmentation of both the alpha and beta genes
B) deletion of the alpha gene and fragmentation of the beta gene
C) deletion of both the alpha and beta genes
D) fragmentation of the alpha gene and deletion of the beta gene
E) destruction of red blood cells in the bone marrow