Final answer:
Separating a compound typically requires a chemical reaction because the elements within a compound are chemically bonded together, as opposed to mixtures which can be separated by physical means without changing their composition. The option (A) is correct.
Step-by-step explanation:
Separating a compound generally requires a chemical reaction. This is because compounds are substances where two or more elements are chemically combined, and it takes a chemical change to break those bonds. For example, table salt (NaCl) is a compound consisting of sodium and chlorine and can only be decomposed into its elements by a chemical process such as electrolysis, which uses an electrical current to produce hydrogen and oxygen gases from water, another compound.
On the contrary, mixtures can often be separated by physical changes because their components are not chemically bonded and can be separated without altering the composition of the substances in question. Therefore, option (A) is correct.