What major natural resource has greatly influenced the economy of the Pacific Northwest?

A. gold and silver
B. coal and natural gas
C. water and oil
D. timber

The major natural resource that has greatly influenced the economy of the Pacific Northwest is D. timber.

To arrive at this answer, you can consider the geographical qualities of the Pacific Northwest region and its historical significance. The Pacific Northwest, composed of states like Oregon, Washington, and parts of Idaho and Montana, is known for its vast forests that are abundant in timber resources. This natural resource has played a critical role in shaping the economy of the region.

Timber has been a key driver of economic activities in the Pacific Northwest, contributing to industries such as logging, timber production, woodworking, and paper manufacturing. The region's forested lands have been a valuable source of timber for construction, fuel, and other industries, both regionally and globally.

Additionally, the presence of dense forests has led to the establishment of numerous timber-related industries and the creation of many jobs in the Pacific Northwest. For many years, the logging and timber industries have continued to be major contributors to the regional economy.

Therefore, the major natural resource that has greatly influenced the economy of the Pacific Northwest is timber.