One parent has curly hair the other has straight hair and their child has wavy hair this an example of

The correct answer is C. DNA or protein sequences of shared genes.

Explanation:

Evolution is a major theory in biology that purposes over time organisms change and they even led to new species due to changes or mutation in genes and observable traits. According to evolution, related organisms evolved from a common ancestor and therefore they have similar DNA or proteins sequences that lead to common features.

According to this, the most accurate way to know whether two or more organisms are related or not or their evolutionary relationship is through DNA or protein sequences of shared genes because only organisms that evolved from a common ancestor would share part of their DNA or protein sequences. Also, common behaviors or physical features do not necessarily show an evolutionary relationship.