In order to evenly and effectively paint a rough surface, it is necessary to first sand it and apply primer before applying the paint.

a)to first sand it and apply primer before applying the paint.
b)to sand it and prime it and paint it.
c)to first sand it, then prime it, then paint it.
d)to first sand the surface and apply primer before you apply paint to the surface.
e)to sand the surface, apply primer to the surface and then paint it.

OA A

What is wrong with option (c) and why is (a) the correct answer?