Abstract: I will first explain 0nuBB decay, and then related practical Dirac-Majorana Confusion Theorem (pDMCT), and issues concerning pDMCT. I will also introduce possible alternatives to 0nuBB, and
the quantum statistical approach to overcome pDMCT. Finally, I will compare 0nuBB with 2nuBB to find out which one would be better to discover Majorana property of sub-eV active neutrino.