Federal law prohibits the use of an instrumentality of interstate commerce to threaten another person. A defendant was convicted of violating that statute by using a telephone to threaten another person. She claims that her conviction was unconstitutional because both she and the victim are located in the same state. A reviewing court should -
a) Uphold the conviction, as the use of an instrumentality of interstate commerce triggers federal jurisdiction
b) Overturn the conviction, as it violates the defendant's right to free speech
c) Refer the case to state court for prosecution
d) Suspend the case until a federal victim is involved