What was popular sovereignty used to determine whether or not a state would enter the union as a slave state or free state?

Which of these was one of the most important aspects of washington's presidency a. he did not consider how his actions would affect later presidents b. he came to believe that political parties would be good for the country. c. he insisted that congress make specific rules about the duties of the president d. he did not take advantage of the opportunity to keep the power the country offered him.