Question

protein sequences in one organism that resemble those of another suggest a
shared ancestry
lack of evolutionary
relationship
coincidence
great number of
mutations

Explanation:

In biology (a subfield of Natural Science), the similarity of protein sequences between organisms is a key piece of evidence for shared ancestry (evolutionary relatedness). Similar protein sequences imply that organisms may have evolved from a common ancestor, as changes in protein sequences occur over time with evolution. The other options are incorrect: "lack of evolutionary relationship" contradicts the concept, "coincidence" is unlikely for such molecular-level similarities, and "great number of mutations" would likely lead to less similarity, not more.

Answer:

A. shared ancestry (assuming the first option's full text is "shared ancestry")