Deadly Accuracy Rage Power

Does the extra bonus to crit confirmations stack with Accurate Stance or does it replace the bonus of Accurate Stance?

Example of level 4 Unchained Barbarian is it:

A) +4 BAB, +STR, +2 from Accurate Stance, +4 Deadly Accuracy, +Miscellaneous bonuses to hit, +1d20 = Crit confirmation roll

or

B) +4 BAB, +STR, +4 Deadly Accuracy, +Miscellaneous bonuses to hit, +1d20 = Crit confirmation roll

B. You're doubling the bonus, not adding a new bonus.

Awesome!

Thanks!

BTW, if you are going to go this route with the UC Barbarian, Get crit focus. That is a +4 to confirm crits, which is essentially doubling your Deadly accuracy.