If aqueous iodine is added to a solution containing vanadium ions, $\text{V}^{2+}$, each $\text{V}^{2+}$ ion gives up one electron. What property of transition elements is being shown by this reaction?
- ATransition elements have variable oxidation states.
- BTransition elements form a stable $1+$ ion.
- CTransition elements are oxidising agents.
- DTransition elements can act as catalysts.