Jenny was interested in studying how much gas a car uses at different speeds. Jenny did one test with her mother's car and found that it used about 3 percent more gas when speed increased by 5 miles per hour.
How can Jenny make the results of her investigation more reliable?
A.
avoid recording any data during the experiment
B.
communicate her results immediately after the one test
C.
redo the steps of the experiment in a different order
D.
repeat the investigation several times