Concept:Soda lime is the alkaline mixture used to dry or absorb gases and to prepare methane in the laboratory.Explanation:Soda lime is not a single compound.It is prepared by mixing caustic soda, NaOH, with slaked lime, Ca(OH)2.When sodium ethanoate is heated with soda lime, decarboxylation occurs and methane gas is produced.The active chemical constituents of soda lime are therefore sodium hydroxide and calcium hydroxide.Answer:A. Ca(OH)2 and NaOH