Which item fits appropriately in the blank?

The correct answer is D.

According to the principle of the division of powers, in the US, the power of the state is splitted in three branches: legislative, executive and judiciary. Moreover, there is a system of Checks and Balances through which each of the powers supervises the other two to prevent that any of them gathers too much power as to overrule the others.

Within the system of Checks and Balances, the judiciary branch has the power of judicial review, through which it can abolish laws and governmental policies, produced by the legislative and executive powers respectively, if it considers that such actions are violating the US Constitution.

#1 im pretty sure its a.