Which of the following sets does not contain isoelectronic species?...

Which of the following sets does not contain isoelectronic species?
(a) \( \mathrm{BO}_{3}^{3-}, \mathrm{CO}_{3}^{2-}, \mathrm{NO}_{3}^{-} \)
(b) \( \mathrm{SO}_{3}^{2-}, \mathrm{CO}_{3}^{2-}, \mathrm{NO}_{3}^{-} \)
\( \mathrm{P} \)
(c) \( \mathrm{CN}^{-}, \mathrm{N}_{2}, \mathrm{C}_{2}^{2-} \)
(d) \( \mathrm{PO}_{4}^{3-}, \mathrm{SO}_{4}^{2-}, \mathrm{ClO}_{4}^{-} \)
W