Suppose That a Particular Chemical Substance a Is "Pure" [Contains

Multiple Choice

Suppose that a particular chemical substance A is "pure" [contains no "impurities"], and that it can be chemically decomposed into two other pure materials B and C. What conclusion can be draw from this?

A) A must be a chemical compound.
B) B and C must be chemical compounds.
C) B and C must be elements.
D) A must be an element.
E) Nonsense-- it is impossible to decompose a pure substance into two other materials.