The correct answer is D. George washing was appointed as the supreme commander of the continental army.
The Second Continental Congress took place in May of 1775. At this time, the colonists were still considered part of the British empire. This shows that options A and C are incorrect, as these actions do not happen until the colonists win their independence from Britian.
Letter B is incorrect as well, as the Articles of Confederation (America's first constitution) was not developed until 1777 and was not approved until 1781.