The spelling of the word "MARCDN" can be explained through the International Phonetic Alphabet (IPA). The first sound, "M," is pronounced as /m/. The second sound, "A," is pronounced as /ɑ/. The third sound, "R," is pronounced as /r/. The fourth sound, "C," is pronounced as /k/. The fifth sound, "D," is pronounced as /d/. The sixth sound, "N," is pronounced as /n/. Therefore, the correct spelling of the word "MARCDN" represents the sounds /mɑrkdn/.