Which Statement Regarding Myoglobin in Antarctic Fish Is True

Which statement regarding myoglobin in Antarctic fish is true?

A) All icefish have nonfunctional myoglobin.
B) Mutations that eliminated myoglobin function occurred independently in four lines of icefish.
C) Mutations that eliminated myoglobin function occurred once in early icefish evolution and have affected six species in different lineages.
D) Identical mutations that eliminated myoglobin function occurred in four separate lineages of icefish.