In all of the below lim is used for the limit as n approaches infinity:
6n^2
lim -------- = 0
(n^2) log n
Hence (n^2) log n is asymptotically faster growing than 6n^2. Thus
6n^2 = O(n^2 log n), 6n^2 != Omega(n^2 log n), 6n^2 != Theta(n^2 log n)
A1 is the faster algorithm.