How did the seven years war end the myth of british invincibility in the minds of the american colonists while making them more confident in their own military strength

The main way in which the Seven Years War did this was because although the war technically ended in a British Victory, the British suffered heavy losses--meaning that the colonists saw that the British were at least somewhat militarily vulnerable. 

Iwould say a, due to the fact these routes display many things that would be useful and provide explanations for how states are known.