A ground-state electron in a calcium atom might have which of the following sets of quantum numbers?
a) n=1, l=0, m=0, s=+1/2
b) n=2, l=1, m=0, s=-1/2
c) n=3, l=2, m=1, s=+1/2
d) n=4, l=3, m=2, s=-1/2