Which Supreme Court case granted states the right to regulate private businesses providing essential public services?

The correct choice is Munn v. Illinois, which addresses the power of states to regulate private enterprises that serve a public function. In this landmark decision, the Supreme Court upheld a state law that regulated grain elevator rates, asserting that private businesses providing essential services could be subject to government oversight to protect the public interest. The Court established that if a business is conducting a public service, the state has the authority to impose regulations to ensure fair pricing and accessibility.

This case has had a lasting impact on the regulatory environment, particularly in industries such as utilities and transportation that are essential to the public. By affirming the state's role in economic affairs, Munn v. Illinois reinforced the principle that even private businesses are subject to state laws when they serve a significant public need, thereby allowing for the protection of consumers and maintaining order in the market.