A is something I would do without fail. Missing words and awkward phrases are really easy to do if you've been at it for awhile.
B is also a good idea. Especially the grammar check.
C and D are not things that I would do. Friends don't catch everything. And marked up copies should probably be reprinted and read a fresh using A and B.
I don't know how to pick just 1 of A or B. I think B is something you can turn on and easily correct what you are doing. I'll pick B but don't be surprised if A is the answer.