In the ring test of `NO_(3)^(-)` ion, `Fe^(2+)` ion reduces nitrate ion to nitric oxide, which combines with `Fe^(2+)` (aq) ion to form brown complex .
Write the reactions involved in the formation of brown ring.
A. If both assertion and reason are correct and reason is correct explanation for assertion.
B. If both assertion and reason are correct but reason is not correct explanation for assertion.
C. If assertion is correct but reason is incorrect.
D. If both assertion and reason are incorrect.