Available options:
a). shine as he moves the mop over the surface.;
b). are red and black and there are several mop outs going.;
c). are covered with black powder.;
d). are as shiny as they were before he mopped many times in his life.;Choose from options above and answer: What most naturally follows?

A man is mopping inside an airy building. the floors
Answer:
a).