When U.S. farmers in the Southwest irrigate their land, salt in the ground soil leaks into the Colorado River. The Colorado River has become so salty that Mexican farmers further down the river cannot irrigate their own land and Mexican crops have been devastated. This situation constitutes a negative externality because:

Other things held constant, when the general price level changes:

a. we move along the aggregate demand curve. b. we shift the aggregate demand curve to the right. c. we shift the aggregate demand curve to the left. d. we shift the aggregate supply curve to the right. e. we shift the aggregate demand curve to the left.

How much revenue will the government raise each week from the tax?

A. $8 million
B. $10 million
C. $20 million
D. $40 million