The correct decreasing order for metallic character is

A metal is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically malleable (they can be hammered into thin sheets) or ductile (can be drawn into wires)

On moving top to bottom of the periodic table metallic character increases and on moving left to right metallic character decreases.

Metallic character is directly proportional to the atomic size.

The correct order of atomic size of the given elements is $Na > Mg > Be > Si > P$.

Hence, correct order of metallic character is $Na > Mg > Be > Si > P$

All these elements are form 3rd period except beryllium which is from second period

Na is an alkali metal

Mg and Be are alkaline earth metals,

Phosphorous belongs to a group which is commonly called as pnicogens.

Si belongs to 14th group