The correct order of density of $\mathrm{Be}, \mathrm{Mg}, \mathrm{Ca}, \mathrm{Sr}$ is

$\mathrm{Ba}, \mathrm{Ca}$ and Sr form halide hydrates. Their formulae are $\mathrm{BaCl}_2 \cdot x \mathrm{H}_2 \mathrm{O}, \mathrm{CaCl}_2 \cdot y \mathrm{H}_2 \mathrm{O} \cdot \mathrm{SrCl}_2 \cdot z \mathrm{H}_2 \mathrm{O}$. The value of $x, y, z$ respectively are

The correct order of decomposition temperature of $\mathrm{MgCO}_3(X), \mathrm{BaCO}_3(Y), \mathrm{CaCO}_3(Z)$ is

Identify the correct statements from the following.

(A) $$\mathrm{BeSO}_4$$ is soluble in water.

(B) BeO is an amphoteric oxide.

(C) CO can be obtained by heating $$\mathrm{CaCO}_3$$ at $$1070-1270 \mathrm{~K}$$.