The role of the president as chief executive officer and head of the federal bureaucracy was clearly established

Explanation:

As Chief Executive the president can: implement policy, supervise the executive branch of government, prepare executive budget for submission to congress, and appoint and remove executive officials. The head of government is the chief officer of the executive branch of a government, often presiding over a cabinet.

according to classical republican political theory, which democratic republics would function best?

a.   small republics, with people who had similar interests

b.   large republics, with people who had competing interests

c.   republics made up entirely of landowners

d.   republics made up entirely of servants