A running cheetah begins to slow down. For each meter the cheetah travels, its speed changes by −3.4−3.4 kilometers per hour. The cheetah travels a total of 21.5 meters. What is the total change in the cheetah's speed during this time?
A. 73.1
B. 71.9
C. 18.1
D. -18.1
E. -71.9
F. -73.1