X, Y and Z are three elements in the third period. When X is reacted with chlorine, a liquid product is formed. When Y reacts with chlorine, a solid product is formed; this dissolves in water to make a solution of pH $7$. When Z reacts with chlorine, a solid product is formed; this dissolves in water to make a solution of pH $6$. Which of these elements conduct electricity well?
- AX and Y
- BY and Z
- CY only
- DZ only