For each of the following molecules, put stars on some of the carbon atoms such that starred

Question:

For each of the following molecules, put stars on some of the carbon atoms such that starred carbons are bonded only to unstarred carbons and unstarred carbons are bonded only to starred carbons. It may not be possible to do this in all cases.
(a) Benzene;
(b) Naphthalene;
(c) Azulene.