The event that happened AFTER the conclusion of the French and Indian War is the passing of the Stamp Act.
The French and Indian War ended in 1763, while the Stamp Act was passed by the British Parliament in 1765 as a way to help pay for the war's expenses.
The other options (establishing colonies, the period of salutary neglect, and the passage of the Navigation Acts) occurred before or during the war rather than after it.