The correct decreasing order of priority for the functional groups of organic compounds in the IUPAC system of nomenclature is
(a) - COOH - SO3H - CONH2 - CHO
(b) - SO3H - COOH - CONH2 - CHO
(c) - CHO - COOH - SO3H - CONH2
(d) - CONH2 - CHO - SO3H - COOH