The correct answer is a government limited by the terms of the Constitution.

• Constitutional government
  • The core element of constitutional government is the existence of a Rule-of-Law or set of basic laws that bind both public office-holders and all members of a society within a given territory.
  • Presently most states avail of a constitution, which directs the organization of the state, the relations between the public offices within the state, as well the human and civil rights of the individual.    
  • The Constitution seeks to regulate political power.
  • Constitutional government means a limited government.
  • A constitutional government is conducted according to rules and principles which are binding on all political actors and which therefore help to constrain the unfettered excise of power by separating it or dividing it.
  • Constitutional government is defined by the existence of a constitution—which may be a legal instrument or merely a set of fixed norms or principles generally accepted as the fundamental Law of the polity—that effectively controls the exercise of political power.
  • The essence of constitutionalism is the control of power by its distribution among several state organs or offices in such a way that they are each subjected to reciprocal controls and forced to cooperate in formulating the will of the state.
  • Constitutional government in essence is about constitutionalism which is about limited government. In many cases, constitutional government is used interchangeably with “constitutionally limited government” or limited government. Hence, Option 4 is correct.