The structures of `O_(3)` and `N_(3)^(-)` are:
A. Both (A) and (R) are true and (R) is the correct explanation of (A)
B. Both (A) and (R) are true and (R) is not the correct explanation of (A)
C. (A) is true and (R) is false
D. (A) is false but (R) is true