Final answer:
George Washington showed leadership by condemning force and promoting peaceful resolution during the militia's threat against Congress, ultimately using military action as a last resort.
Step-by-step explanation:
George Washington displayed leadership by condemning the use of force against Congress and calling for a peaceful resolution. When the militia threatened the federal government, Washington, who believed neither military nor civil governance should be disrespected, issued a proclamation expressing willingness to use the militia to enforce the law if necessary.
First, however, he sent a peace commission to negotiate. Only when that failed did he call up 12,000 troops to address the insurrection, leading to its collapse and the arrest of twenty men, two of whom were later pardoned by the president himself.
Therefore, the correct answer to how George Washington displayed leadership is C) He condemned the use of force and called for a peaceful resolution.