Tom I agree with you that D is 'best practice'. I believe "A" is factually correct as worded except that the tube/shim is in FRONT of the rear bearing (ie between the front and rear!)
I also 100% agree that I sure as heck wouldn't arbitrarily tighten that pinion nut either!!!!
I just finished complete rebuild of three 4:10 LSD diffs. Complete rebuild including all bearings. It was a BEAR!!! I wont do it again unless under extreme duress. The thread is somewhere probably in the gearbox/trans/diff forum
74 GTV with 10548's and Ingram pump
71 Spider 1750 BOMBER ; 1995 LS 78K tight fast car