Answer:
Stratosphere
airline pilots prefer to operate in the stratosphere
The correct answer is b: cattle on rangeland. A point source of pollution occurs from a single identifiable and usually spatially narrow source. These sources of pollution are usually relatively easily to quantify and manage. In contrast, a non-point source of pollution, such as cattle on rangeland or irrigated agriculture, is variable on both spatial and temporal scales. These sources of pollution are difficult to quantify and manage.
