How to match DIMMs?

I have a P9X79 Deluxe motherboard and two 4x4GB sets of RAM for a total of 32GB of RAM.

Should I:
A: put one set of RAM into {A1, A2, B1, B2} and the other into {C1, C2, D1, D2}, OR
B: put one set of RAM into {A1, B1, C1, D1} and the other into {A2, B2, C2, D2}?

Also, how sure are you that your answer's correct? (Which I only ask because a lot of the advice that I've gotten has been later retracted. I'm cool with an uncertain answer, but I'd just like to know how good my information is.)

PS- I know that both work, but I've been told that matching it up correctly makes it easier to balance the settings for overclocking since different sets of matched DIMMs can have slightly different characteristics.

Use the blue dimm slots for 4 modules.
A1,B1 and D1,C1 it's spelled out in the manual.
8 modules fill in the remaining dimms.