OPT:
[a]. at the back of the tube reverses and reverts back to the front.;
[b]. is taken off, tire irons are put in, and the tube is removed.;
[c]. pans to reveal the finished park.;
[d]. is scraped, he puts gel over the site, then wraps it with big cloth on both wheels.;Choose from options above and answer: What most naturally follows?

A man gives a tutorial on how to change a bike tube. the wheel
Answer:
[b].