Assertion: `Ce^(4+)` is used as an oxidising agent in volumetric analysis.
Reason: `Ce^(4+)` has the tendency to attain `+3` oxidation state.
A. If both (A) and (R) are correct and (R) is the correct explanation of (A).
B. If both (A) and (R) are correct, but (R) is not the correct explanation of (A).
C. If (A) is correct, but (R) is incorrect.
D. If (A) is incorrect but (R) is correct.
