Final answer:
The best argument against the constitutionality of the ordinance is that it is overly broad, as it fails the test of content neutrality.
Step-by-step explanation:
The best argument against the constitutionality of the ordinance is option (B) The ordinance is overly broad.
Content restrictions on speech must be content neutral. If a limit is placed on a particular kind of speech or form of expression, it must be applied to all instances of that kind, without favoring one over the other. The ordinance banning all First Amendment activities on the beach fails this test because it restricts all forms of expression, regardless of their content. It therefore violates the principle of content neutrality.