Correct Response: D. The sounds /b/ and /v/ are described as being interchangeable in the student's first language. This implies that the rules for these sounds in the student's first language are less restrictive than in English, where those two sounds are not interchangeable but rather independent phonemes. A is incorrect because English is not a tonal language, plus no information is given about tonality in the student's first language. B is incorrect because the consonant sounds /b/ and /v/ are always voiced; they cannot be voiced in one language and voiceless in another. Lastly, since no examples are given for consonant-vowel sequences in the student's first language, one cannot conclude that such sequences are more complex in the student's first language than in English, making C incorrect as well.