(a) is an unbiased method analogous to blind orchestral auditions. (b) and (c) are not. (a) is also basically identical to hiring by github unless the candidate illegaly uses proprietary code as their sample. (From her article: "...not all programmers own the rights to their code..." in which case I can't look at it when hiring.)

The entire article is about how using github (i.e. evaluating code with the human absent, i.e. the closest thing [1] we currently have to blind auditions) is "biased" against women.

[1] Maybe we'll have something closer when starfighter comes out. I look forward to it.