The reason why ethics differs when we're talking about people, companies, nations is that all of these have interests which may differ. What happens then with differing interests is that it also lead to different moral and value systems which again in turn lead to different ethics. Most usually, the actual source why ethics differ is either due to the interests or wishes of a particular social group mentioned here.
The answer should be A because they are the only one you could actually do it to. You can’t hurt a baby or a pregnant women and you can’t wrap your arms away a fat person.