$31)$ Which of the following statements is true?

A$)$ If a state child labor law is stricter than the federal law, the federal law supersedes the state law.

B$)$ If a state child labor law is stricter than the federal law, the state law applies.

C$)$ If a federal labor law is stricter than the state law, the state law supersedes the federal law.

D$)$ Federal law always supersedes state law.