Imagine That a Researcher Is Studying a Mouse That Carries

Imagine that a researcher is studying a mouse that carries a mutation in Pax7-a gene that is involved in muscle development. To his surprise, these Pax7 mutant mice appear relatively normal. What is a possible explanation for this?

A) Other members of the Pax gene family have redundant functions in muscle development (and can compensate for the Pax7 mutation) .
B) The normal copy of Pax7 on the corresponding homologous chromosome is sufficient for mouse survival.
C) These Pax7 mutant mice may have a synonymous mutation.
D) All of these choices are correct.