Phonemes are important because . In the English language the 47 phonemes A. they are the largest unit of speech that can change the meaning of a word ; consist of only consonant sounds. B. they are the smallest unit of speech that can change the meaning of a word ; consist of only vowel sounds. C. they are the smallest unit of speech that can change the meaning of a word ; consist of only consonant sounds. D. they are the smallest unit of speech that can change the meaning of a word ; consist of both vowel and consonant sounds. E. they are the smallest unit of speech common to all languages; consist of both vowel and consonant sounds