The following options are precedents that George Washington set during his presidency:
B. he chose well-known leaders to run his executive departments and serve as his advisors.
D. he chose to not run for a third term.
Option A is incorrect because the establishment of the judicial system, including the Supreme Court with nine justices, was formalized through the Judiciary Act of 1789, but Washington did not set a precedent for this specific number.
Option C is also not accurate in that Washington did not establish a position specifically titled "Tax and Tariff," though he did address fiscal matters through the Department of Treasury.
So the correct answers are B and D.