Answer:
B 5 meters per second
Explanation:
Pick two points on the graph, and find the slope.
For example, you can use the points
(0, 8500) and (1700, 0)
slope = (difference in y)/(difference in x)
slope = (0 - 8500)/(1700 - 0) = -8500/1700 = -5
The slope is negative because the plane was losing altitude as it descended.
It descended at a rate of 5 meters per second.
Answer: B 5 meters per second