Under their police powers, states can enact and enforce all of the following EXCEPT

• A. Criminal codes.
• B. Laws requiring children to attend school.
• C. Restrictions on the availability of pornographic materials.
• D. The regulation of interstate commerce.

Answer: (C)

States have police powers to protect public health, safety, morals, and welfare. That lets them create and enforce criminal codes, require children to attend school, and regulate activities tied to local moral or safety concerns (with limits like respect for free speech in the case of obscenity). But regulating commerce that crosses state lines is a federal power under the Commerce Clause, and the Dormant Commerce Clause restricts states from unduly burdening or discriminating against interstate trade. So while states can handle many intrastate matters, they cannot regulate interstate commerce in the way described, which is why that option is the exception.