Why were english, and later british, explorers interested in the pacific northwest

Great Britain was interested in the PNW( Pacific Northwest) because of commercial potential and make use of the Natural Resources.

In A. D. 458, a Chinese adventurer named Hwui Shan crossed the Pacific to Mexico, and then followed the Japan current north to Alaska. Centuries later, in September 1513, Vasco Nunez de Balboa "discovered" the Pacific after struggling across the swampy Isthmus of Panama. Following that momentous event, Spain dispatched a number of legendary captains to the West Coast of North America, including Hernando Cortez, Juan Rodriguez Cabrillo, and Bartolome Ferrelo. In 1579, Britain's pirate Francis Drake sailed off the Oregon coast; during the early 1740s, Vitus Bering opened the North Pacific to Imperial Russia; during the late 1700s, English captains James Cook and George Vancouver charted the Pacific including the bays and inlets of Puget Sound (Vancouver); and in 1786, Comte de La Perouse, representing France, sailed to the Queen Charlotte islands. 

C. it's a true fact. i know because we are studying about the great depression. so it best illustrates a claim of fact. thx. have a wonderful day!