The least useful technique in the study is C. Comparisons of items eaten for food. This is the least scientific method of studying two different species because many animals can want the same food and not have any relation with each other. It isn't considered an important factor in determining the similar characteristics of species, especially in terms of genetic makeup.
oxygen and carbon dioxide exchanged in the lungs
Protein can be reversed to make glucose so the answer is protein
I believe the answer you are looking for is
A) true
