Arlene McCrae is a school-board member in Jordan County. Appalled by the amount of vending machines in the schools, she convinces the state legislature to pass an ordinance that no school or stores may have a vending machine within 600 feet of any school or daycare center. ACME, a vending machine supplier, questions whether the regulation is valid and is told that it is a valid exercise of the jurisdiction's police power to protect its citizens. Convenience stores and vending machine suppliers balk at the regulation and challenge it in court claiming that the law impermissibly affects interstate commerce. Restrictions on states' authority to pass laws that substantially affect interstate commerce are referenced by which of the following?

a. The Tracking Clause
b. The superior Commerce Clause
c. The interstate trafficking Commerce Clause
d. The State Authority Clause
e. The dormant Commerce Clause