[Junk Food] Denise McCrae Is a School-Board Member in Mariposa

[Junk Food] Denise McCrae is a school-board member in Mariposa County. Appalled by the amount of junk food in the schools, she convinces the state legislature to pass an ordinance that no stores may sell any unhealthy junk food within 600 feet of any school or daycare center. A political science teacher 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 balk at the regulation and challenge it in court claiming that the law impermissibly affects interstate commerce.
-Which of the following is the best definition of the term "police power"?

A) The residual powers retained by each state to safeguard the health and welfare of its citizenry.
B) The residual powers retained by the federal government to enforce valid laws and regulations.
C) The powers granted to local government to enter residences without a search warrant.
D) The powers granted to state governments to tax for the purposes of having law enforcement.
E) The powers granted to state government to imprison citizens of other states who commit crimes within a state.