The answer is a because if you look at the bone structure in each animal, you would notice how similar they look to one another, and all of the animals above use their legs for the same function which is walking which can suggest that all had a common ancestor.
hopefully this helps
The question that could be investigated through scientific research is B. Does a newly synthesized chemical reduce bacteria? The answer is B. Because the other questions aren’t science questions. They are bias.
It's the naming/classifying system
The first word in it is the genus and the second word is the species. The first letter in the genus has to be capitalized and both words have to be underlined
