Which is used to reduce the acidity of soil?

Given below are two statements:
Statement $I$: Both $CaCl_2 \cdot 6H_2O$ and $MgCl_2 \cdot 8H_2O$ undergo dehydration on heating.
Statement $II$: $BeO$ is amphoteric whereas the oxides of other elements in the same group are acidic.
In the light of the above statements,choose the correct answer from the options given below:

Match Column $(A)$ with the appropriate options in Column $(B)$.

Column $(A)$	Column $(B)$
$(a)$ $BeO$	$(p)$ Amphoteric
$(b)$ $MgCO_3 \cdot CaCO_3$	$(q)$ Dolomite
$(c)$ $BeCl_2$	$(r)$ Covalent
$(d)$ $Al(OH)_3$	$(s)$ Basic

An element $X$ with the electronic configuration $1s^2, 2s^2 2p^6, 3s^2$ would be expected to form the chloride with the formula

Thermal stability of $MCO_3$ is in order:

The element having atomic number $56$ belongs to