Which element is responsible for the crimson red color in fireworks?

The solubility order for alkali metal fluoride in water is

Compound $A$ reacts with $NH_4Cl$ and forms a compound $B$. Compound $B$ reacts with $H_2O$ and excess of $CO_2$ to form compound $C$,which on reaction with saturated $NaCl$ solution forms sodium hydrogen carbonate. Compounds $A, B$ and $C$ are respectively:

Select the correct statement from the following.

Which element of group-$1$ has the highest hydration enthalpy? Why?

$Al +$ aq. $NaOH$ (excess) $\longrightarrow P + Q$. $P$ and $Q$ are