Set S={9,2,0.3,722}. Which option lists the rational and irrational numbers in S correctly?
a) Rational: {9,722} ; Irrational: {2,0.3}
b) Rational: {9,0.3} ; Irrational: {2,722}
c) Rational: {9,0.3,722} ; Irrational: {2}
d) Rational: {9,0.3,2} ; Irrational: {722}