Answer:
B. It established the judicial review process, which created a balance of power between the executive, legislative, and judicial branches of government.
Step-by-step explanation:
The case Marbury v. Madison was a US Supreme Court case that created the principle of judicial review. It means that since then, American courts have the power to remove laws that are considered against the US Constitution. Until that moment, there was no rule that determined that.
This was very important because it determines the supremacy of the US Constitution, and also creates a balance between the branches of the government.