Which of the following statements about the physical geography of north america is true? a. the mississippi drainage basin is the fifth largest in the world. b. the largest tributary of the mississippi is the arkansas river. c. the most geologically active region of north america is found along the west coast. d. the ancient rock of the canadian shield covers about one-fourth of canada.

The correct answer is - C. The most geologically active region of North America is found along the West Coast.

The West Coast of North America is by far the geologically most active on the continent. It is part of the so called ''Ring of Fire''. Here we have the boundaries of the North American tectonic plate and the Pacific tectonic plate which causes lot of geological activity in the region. Earthquakes are a common occurrence in this part, a big rift valley stretches through California and it is getting bigger and bigger over time, and also the biggest volcano nowadays is found in this region, more specifically under the Yellowstone National Park in the northwestern part of the United States.