X and Y are two elements in Period 3 of the Periodic Table. Element X conducts electricity better than element Y. Element Y has a melting point that is higher than that of element X. Which formula is a compound made from element X and element Y?
- A$\text{MgS}$
- B$\text{Mg}_2\text{Si}$
- C$\text{NaCl}$
- D$\text{SiCl}_4$