In which of the following pairs of ions, the higher oxidation state in aqueous solution is more stable than the other?
I. `TI^(+), TI^(3+)` II. `Cu^(+),Cu^(2+)`
III. `Cr^(2+),Cr^(3+)` IV. `V^(2+),VO^(2+)(V^(4+))`
A. I, II
B. II, III
C. II, IV
D. II, III, IV