Which of the following substances can be used for drying gas

Q. Which of the following substances can be used for drying gases?

Q. Which of the following substance can be used for drying neutral and basic gases?

Q. Which of the following can be used to dry $HCl$ gas?

Q. (i) How is ammonia gas prepared in laboratory starting from NH₄Cl? State the conditions and balanced equation for the preparation.
(ii) How is gas collected in a gas jar?
(iii) Name the substance used for drying ammonia gas. Why cannot substances such as conc. H₂SO₄, anhydrous calcium chloride and phosphorus pentoxide be used for drying ammonia gas?

Q. Among $Ca{Cl}_2,H_{2}S{O}_4$ and $CaO$, which compound can be used for the drying of ammonia gas? Why?