Concept:The civil service is the administrative body that carries out government decisions.
Explanation:The civil service implements the policies of the government in power.
It provides services to the public and keeps the machinery of government running.
Enactment of laws is the function of the legislature.
Settlement of disputes is the function of the judiciary.
Appointment of ministers is done by the executive.
Thus, the key function of the civil service is policy implementation.
Answer:D. Implementation of policies.