The answer is B. But i don’t know how to explain it
A volcanic eruption is what most scientists believe created the Richat Structure. Hope this helps.
In the Treaty of 1818, Britain and the United States agreed to joint control of the Oregon County for 10 years. During this Convention of 1818, Britain and united states of America also agreed to maintaining 49th parallel as the northern boundary of the Louisiana territory between the Lake of Woods and the Rocky mountains. <span />
