Which of the following are isoelectronic and isostructural?

Which of the following are isoelectronic and isostructural?
NO3-, CO3 -2, SO3, CLO3-
A. NO3- ,CO3 -2 ,
B. SO3, NO3 -
C. CLO3-, CO3-2
D. CO3-2, SO3
ONLY ONE CORRECT AND WHY EXPLAIN HOW?

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