Why Is Commercial Speech Not Entitled to Full First Amendment

Why is commercial speech not entitled to full First Amendment protection, even though protections of such have increased in recent times?

A) Regulating commercial speech protects gullible consumers from rampant overspending.
B) Commercial entities have a history of making reliable advertising claims, and the Supreme Court wanted that to continue.
C) Commercial speech is not political speech, so it can be regulated more heavily.
D) Commercial speech always targets minors, who need greater protection.