What is the slope of the line and what does it mean in this situation?
 A. The slope is –500–500 . This means that the bird descends 500 m each minute.
 B. The slope is –350–350 . This means that the bird descends 350 m each minute.
 C. The slope is 350. This means that the bird ascends 350 m each minute.
 D. The slope is 500. This means that the bird ascends 500 m each minute.