Read the passage given below and answer the following questions:
Within the 3d series, manganese exhibits oxidation states in aqueous solution from +2 to +7, ranging from `Mn^(2+)(aq)` to `MnO_(4)^(-)` (aq). Likewise, iron forms both `Fe^(2+)(aq)` and `Fe^(3+)(aq)` as well as the `FeO_(4)^(2-)` ion. Cr and Mn form oxyions `CrO_(4)^(2-) , MnO_(4)^(-)`, owing to their willingness to form multiple bonds . The pattern with the early transition metals-in the 3d series up to Mn, and for the 4d, 5d metals up to Ru and Os—is that the maximum oxidation state corresponds to the number of ‘‘outer shell’’ electrons. The highest oxidation states of the 3d metals may depend upon complex formation (e.g., the stabilization of `Co^(3+)` by ammonia) or upon the pH (thus `MnO_(4)^(2-)` (aq) is prone to disproportionation in acidic solution). Within the 3d series, there is considerable variation in relative stability of oxidation states, sometimes on moving from one metal to a neighbor, thus, for iron, `Fe^(3+)` is more stable than `Fe^(2+)`, especially in alkaline conditions, while the reverse is true for cobalt. The ability of transition metals to exhibit a wide range of oxidation states is marked with metals such as vanadium, where the standard potentials can be rather small, making a switch between states relatively easy.
(Cotton, S. A. (2011). Lanthanides: Comparison to 3d metals. Encyclopedia of inorganic and Bioinorganic Chemistry.)
In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage.
Assertion: The highest oxidation states of the 3d metals depends only on electronic configuration of the metal.
Reason: The number of electrons in the (n-1)d and ns subshells determine the oxidation states exhibited by the metal.

Explanation

Both `V^(4+)` and `Cu^(+)` have one unpaired electron in the d-orbital. `V^(4+) = [Ar] 3d^(1) , Cu^(+) = [Ar] 3d^(9)`