Which statement about the executive roles of the president of the united states and the queen of england is true? a. the president fills the roles of head of state and head of government. b. the queen fills the roles of head of state and head of government. c. the president fills only the role of head of state. d. the queen is head of government, and the prime minister is head of state. e. the president's role is ceremonial, with congress serving the roles of head of state and head of government.