A mixture of three solids, (A) 4-methoxybenzoic acid, (B) 4-methylaniline, and (C) 2-methylnaphthalene, is dissolved in a test tube using diethyl ether. 2.5 mL of 3.0M HCl is added to the ether mixture, and the test tube is inverted to mix the compounds. Afterwards, two layers appear in the test tube. Which compound(s) are found in the organic layer?