Olfactory GPCR Genes

Olfactory GPCR genes:

A) include sequences encoding amino acids that are highly conserved in mammals.
B) include sequences encoding amino acids that are highly variable between gene family members to permit binding to diverse odorants.
C) probably underwent many duplications under selection pressure in rodents.
D) accumulate more nonsense mutations in species that rely less heavily on smell.
E) All of the above