Response would be correct, as in response to environment.
Answer:
Figure 1-4 shows one with an animation in progress. Work area is the technical name for the gray area surrounding the stage, although many Flash-ionados call it the backstage. ... The Stage is where you draw the pictures that will eventually become your animation.
Explanation:
Mostly bacillus (bacteria with cylindrical/rod shaped morphology) I'm pretty sure, you don't see any type of coccus (bacteria with spherical morphology) with flagella.