Which metal wire is used as a conductor of electricity?

Assertion: In general,transition metals have high melting points.
Reason: More number of electrons from $(n-1)d$ and $ns$ are involved in interatomic metallic bonding.
The correct option among the following is

What is the number of elements present in each series of transition elements?

The hardness of $Cr$ is due to $......$ and metallic lustre is due to $.......$

Identify the correct statements from the following: $(i)$ $Ti(IV)$ is more stable than $Ti(III)$ and $Ti(II)$ $(ii)$ Among $3d-$series elements (from $Z=22$ to $29$) only copper has positive reduction potential $(M^{2+} / M)$ $(iii)$ Both $Sc$ and $Zn$ exhibit $+1$ oxidation state

Technetium,the element below manganese in the Periodic Table,would be expected to have high values for its:
$(I)$ melting point
$(II)$ boiling point
$(III)$ density