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.