Alkali metals and alkaline earth metals have the characteristics of :

The correct options are
B very high oxidation potentials
C solubility in liquid ammonia
Alkali metals and alkaline earth metals have low melting points.

They have very high oxidation potentials.

They readily lose electrons and are strong reducing agents.
They have very good solubility in liquid ammonia.

So, both options $B$ and $C$ are correct.