Select the correct answer. Which statement about the executive role of the president of the United States is true? A. The president fills the roles of head of state and head of government. B. The president's only role is the head of government. C. The president's only role is the head of state. D. The president fills the role of the chief justice of the supreme court. E. The president's role is ceremonial, with Congress serving the roles of head of state and head of government.