Beachside City enacts an ordinance that bans the distribution of all printed materials on city streets. Carl opposes the city's latest "revenue-enhancing" measure and wants to protest by distributing handbills. In his suit against the city, a court would likely hold the printed-materials ban to be:
a) constitutional under the First Amendment.
b) not subject to the U.S. Constitution.
c) unconstitutional under the commerce clause.
d) unconstitutional under the First Amendment.