Answer:
Option C, American Robert Gray turning up the regions major river in 1792, is the right answer.
Step-by-step explanation:
For the thousand years, people have inhabited the land of Oregon. There were several Native American tribes when the Europeans arrived in the land. The Chinook, the Paiute, the Cayuse, the Nez Perce etc were some of the major tribes during this time. Though the European explorers were the first to spot the land, they did not set foot on land. However, both Britain and Spain claimed their authority over the land. It was in the year 1792 that Captain Robert Gray, an explorer from America came upon the River Columbia and called the river after the name of his ship.