For each electron in a ground-state Be atom, select the set of quantum numbers that represents it. Check all that apply.

Question

n=1 l=0 ml=-1 ms= +1/2
n=1 l=0 ml=0 ms=-1/2
n=2 l=1 ml=0 ms= -1/2
n=1 l=0 ml=0 ms=+1/2
n=2 l=1 ml=1 ms=+1/2
n=2 1=0 ml=0 ms=+1/2
n=2 l=0 ml=0 ms=-1/2
n=2 l=0 ml=0 ms=-1

I know the top one and the last one aren't correct but I don't know about the others. The hint said,"Make sure you have chosen exactly four answers" why will it have 4?