The visible spectrum of sodium is dominated by two closely spaced bright yellow lines at \(589.0 \mathrm{~nm}\) and \(589.6 \mathrm{~nm}\). The line at \(589.0 \mathrm{~nm}\) is due to a transition from a \({ }^{2} P_{3 / 2}\) level to a lower \({ }^{2} S_{1 / 2}\) level. How many different Zeeman lines would it exhibit in a relatively weak magnetic field?