Select from the following.
A). killing insects
B). Shoot them
C). kill them
D). protect them
E). Extend them
F). Shed them
G). Retract them
H). behave

Fact 1: Threatening behavior by predators causes a porcupine to extend its quills. Fact 2: Puffers are smooth skinned while Porcupines have the characteristic spines or quills. Given the two facts above, what does a porcupine do with its spines when it's threatened?
Answer:
E).