Transition metal and their compounds are used as catalyst in Industry and in biological system for example in the contact process vanadium compounds in the `+5` state `V_(2)O_(5)` and `VO_(3)^(-)` are used to oxidise `SO_(2)` to `SO_(3)`
`SO_(2) + 1/2 O_(2) overset(V_(2)O_(2))rarr SO_(3)`
It is thought that the actual oxidation process takes place in two stages. In the first step `V^(+5)` in the presence of oxide ions converts `SO_(2)` to `SO_(3)`. At the same time `V^(+5)` is reduced to `V^(+4)`
`2V^(+5) + O^(-2) + SO_(2) rarr 2V^(+4) + SO_(3)`
In the second step `V^(+5)` is regenerated from `V^(+4)` by oxygen
`2V^(+4) + 1/2 O_(2) rarr 2V^(+5) + SO_(3)`
The overall process is of course the sum of these two steps.
`SO_(2) + 1/2 O_(2) rarr SO_(3)`
Which of the following ionin volved in the above process will show Para magnetism?
A. `V^(+5)`
B. `V^(+4)`
C. `O^(-2)`
D. `VO_(3)^(-)`
