The figure shows the variation of photocurrent with anode potential for four different radiations. Let \(\mathrm{I}_{\mathrm{a}}, \mathrm{I}_{\mathrm{b}}, \mathrm{I}_{\mathrm{c}}\) and \(\mathrm{I}_{\mathrm{d}}\) be the intensities for the curves a, b, c and d respectively \(\left[f_a, f_b, f_c\right.\) and \(f_d\) are frequencies respectively]

1. A \(f_a=f_b \gt f_c \gt f_d\) and \(I_a=I_b \gt I_c \gt I_d\)
2. B \(\mathrm{f}_{\mathrm{a}} \lt \mathrm{f}_{\mathrm{b}} \gt \mathrm{f}_{\mathrm{c}}=\mathrm{f}_{\mathrm{d}}\) and \(\mathrm{I}_{\mathrm{a}}=\mathrm{I}_{\mathrm{b}}\gt\mathrm{I}_{\mathrm{c}}^{\prime} \gt \mathrm{I}_{\mathrm{d}}\)
3. C \(\mathrm{f}_{\mathrm{a}}=\mathrm{f}_{\mathrm{b}}=\mathrm{f}_{\mathrm{c}}=\mathrm{f}_{\mathrm{d}}\) and \(\mathrm{I}_{\mathrm{a}} \lt \mathrm{I}_{\mathrm{b}} \lt \mathrm{I}_{\mathrm{c}} \lt \mathrm{I}_{\mathrm{d}}\)
4. D \(f_a \gt f_b \gt f_c \gt f_d\) and \(I_a=I_b=I_c=I_d\)