Which Statement Is True About a Single-Payer Health-Care System

Which statement is true about a single-payer health-care system?

A) The government is the only major payer for health care.
B) It is often characterized by universal coverage.
C) The administrative costs of this system are much lower than those of multiple-payer systems (like the United States) because there is only one major payer that all providers deal with for basic health-care services.
D) All of these.