Which of the following BEST describes George Perkins Marsh's contributions to the field of geography? (2 points)
A. He placed an emphasis on using the scientific method to answer questions about geography.
B. He was one of the first people to lead a successful expedition to the North Pole.
C. He developed the coordinate system of latitude and longitude.
D. He identified a connection between human actions and environmental degradation.
E. He invented a navigation device that was reliable at vhf sea.

I think it's  

He identified a connection between human actions and environmental degradation.

Explanation:

I looked it up : )

if triangle abc is congruent to triangle def, their interior angles are congruent, because congruent parts of congruent triangles are congruent (cpctc).

that means ∠d is congruent to ∠a; ∠d is equal to 8x - 2.

interior angles of all triangles add to equal 180 degrees, so you can set the sum of these interior angle values equal to 180 and solve for x.

180 = (8x - 2) + 22 + 72

180 = 8x - 2 + 22 + 72

180 = 8x + 92

88 = 8x

11 = x

x = 11