The noun 'Mathematics' is incorrectly placed at 'A' because a word is required to qualify the succeeding noun 'argument', and thus, either the adjective 'conceptual' or the possessive noun 'gambler's' can replace 'mathematics'. The adjective is already apt at 'B' as it qualifies the noun 'inadequacy'. But, the possessive noun is incorrectly used at 'C' as it is preceded by preposition 'of', and thus, requires a noun [because prepositions are always followed by nouns or gerunds]. Thus, if we interchange 'mathematics' and 'gambler's', the sentence would become grammatically and contextually correct.
The correct order is CBA. Hence, the correct answer is option (a).
Correct statement after corrections: The gambler's argument is a mix of conceptual inadequacy, misinterpretation, irrelevant application of mathematics, and misleading use of language.