The spelling of the word "Kareina" can be explained using the International Phonetic Alphabet (IPA). The first syllable "Ka" is pronounced as /kɑː/, with a long "a" sound. The second syllable "rei" is pronounced as /reɪ/, with a diphthong "ei" sound. The final syllable "na" is pronounced as /nə/, with a schwa sound. Therefore, the correct spelling of this word, "Kareina," is phonetically transcribed as /kɑːreɪnə/.