The genetic information in human and chimpanzee dna shows a high degree of similarity, as humans share about 96-99% of their dna code with chimpanzees. what is an explanation for this similarity?

This similarity can be explained by Charles Darwin's Theory of Evolution. Humans and chimpanzees share a common ancestor wherein a number of million years ago, due to adaptation of their environment, human species branched out and eventually evolved into Homo sapiens. 

The correct answer would be common ancestry.

Common ancestry means that different species have been established from a single parent species or population.

Organisms which share more recent common ancestors tend to have more similarity as compared to the organisms which share an older ancestor.

Humans and chimpanzees also believed to evolved from a common ancestor around 6-7 million years ago.

It is the reason why humans and chimpanzees share around 96-99 percent of the DNA.

the correct answer is b