Observe the following ions

$$ \mathrm{V}^{2+}, \mathrm{Zn}^{2+}, \mathrm{Cu}^{2+}, \mathrm{Fe}^{2+}, \mathrm{Fe}^{3+}, \mathrm{Ti}^{3+}, \mathrm{Sc}^{3+}, \mathrm{Ti}^{4+}, \mathrm{Ni}^{3+}, \mathrm{Co}^{3+}, \mathrm{Cu}^{+} $$

How many ions in the above list have zero magnetic moment?

The order of melting points of $\mathrm{Cr}, \mathrm{Mo}$ and W is

Assertion (A) Mo has the ground state electronic configuration $4 d^5 5 s^1$.

Reason (R) Mo has the highest exchange energy among the second row transition elements.

The correct option among the following is