X is a lustrous, silver-coloured solid under room temperature and pressure conditions. X also conducts heat and electricity well in the solid state. Which statement about X is correct?
- AX is an ionic compound or a metallic element.
- BX is a metallic element or a non-metallic element.
- CX is an alloy or a metallic element.
- DX is an alloy or a non-metallic element.