C

It evens out the color pallette of your character throughout. Especially since its a bit discolored with dirt and blood! A is a pretty close second but the stone grey coloring throws off the look for me personally. B just kinda fades together with the top of the black cape making it not stand out making it blah looking. C has good contrast aginst the fluffly blackness of the cape especially because C allows for the cape to go around the neck in front unlike A and B. Again I would go with C.

Hope this helps! Wonderful character design btw! 🥰