Final answer:
Major Benedict Arnold was likely the individual who felt jealous for not being chosen to lead the military group, especially after George Washington's nomination as commander-in-chief.
Thus, the correct option is 1.
Step-by-step explanation:
The individual who was jealous that he wasn't picked to lead the military group was Major Benedict Arnold. Although not explicitly stated in the information provided, historical context suggests that Arnold might have felt envy or resentment because of scenarios similar to the event on June 15, when George Washington was nominated and accepted the role of commander-in-chief of the Continental Army. Arnold's later actions during the Revolutionary War, which included a plot to surrender West Point to the British, also indicate that he was dissatisfied with how he was treated by the Continental Congress and his peers.
Therefore, the correct option is 1) John.