Which of the following best defines judicial review?

Judicial review is best defined as the ability to invalidate laws that conflict with the Constitution. This principle grants the judiciary the power to assess whether laws or executive actions are in line with constitutional mandates. When a court exercises judicial review, it examines the law in question and determines if it adheres to the Constitution. If the law is found to be in conflict, the court has the authority to nullify it, thereby protecting the supremacy of the Constitution as the highest law of the land. This function is crucial in maintaining a system of checks and balances, as it empowers the judiciary to act as a safeguard against legislative and executive overreach.

The other options do not accurately capture the essence of judicial review. Establishing laws pertains to the legislative branch, interpreting laws aligns with both the judicial role and legislative intent, while executing laws describes the function of the executive branch. Therefore, the distinct role of judicial review in invalidating unconstitutional legislation is what makes the answer correct.