For the first question, the quote that best explains why Washington chose to be neutral in the conflict between the French and the British is:
"Rather, he [Washington] insisted upon a neutral course until the United States could grow stronger."
For the second question, based on the evidence from the text, the reason why Washington rejected the advice of both Jefferson and Hamilton and adopted a policy of neutrality is:
Washington felt that the nation could not afford another war so soon after the Revolution.