D.
A fixed allele is homozygous within a population so D should be the correct answer.
Hope this helps!
Pyroxene and plagioclases feldspar
Its basically saying something (object) at rest is going to stay there until something moves it like an outside object.
This type of classification used to be used when classifying the protostome organisms.
In this type of organism, the oral cavity develops from the blastophore, the initial cavity in the gastrula, an early stage of the development of the embryo.
