Here statement B is correct as with increase in atomic number down the group the tendency to show +2 oxidation state increases due to inert pair effect.

In carbon family, the tendency towards catenation decreases on moving down the group, because the strength of $\mathrm{M}-\mathrm{M}$ bond decreases.

Metallic character always increases on moving down the group. Carbon is strictly non-metallic; silicon is essentially a non-metal in its chemical property; germanium is a semimetal with pronounced metallic properties; tin and lead are truly metallic.

Carbon atom does not form complexes, because it does not have d-orbitals in its valence shell. The other elements of group have d-orbitals in their valence shell, therefore, the tendency to form complexes with covalency higher than four increases on moving down the group.