In mice, black fur is dominant over white fur, and black eyes are dominant over red eyes. assuming the parents are heterozygous for both traits, which of the following is possible?

Two parent mice with black fur have offspring with white hair.

Since both are heterozygous, that means they both have a dominant and recessive allele, but since they have a dominant, that trait is displayed. Since both also have a recessive allele, there is a possibility that they can have offspring with a recessive trait.

In other words, if you have 2 heterozygous parents that show a dominant allele, offspring that display the recessive allele is possible.

Hope this helps :)

This post might have the info you need:

This movement is also referred to as  glacial plucking