Which constitutional amendment protects the words and ideas that are heard on talk radio?
a. the first amendment
b. the second amendment
c. the fifth amendment
d. the eighteenth amendment

It would be the "First Amendment" that protects the words and ideas that are heard on talk radio, since this protects the freedom of speech, which is one of the most important human liberties. 

The Correct Answer is

The First Amendment

Explanation:

Each and every American has the right to speech and Expression and the First Amendment of the Constitution gives this right to the Citizens if America. The First Amendment of the Constitution protects our right to freedom of speech and expression, right to religion, Right to freedom of the press, Right of the people to gather and peacefully protest against the government false policies and petition to the government for redresses of the grievances.