Consider the following statements about the phonological system of the English language and answer the question:

I. The distinction between the sounds /ʃ/ (as in "she") and /tʃ/ (as in "chair") is a contrast between a fricative and an affricate.

II. The English phoneme /ɪ/ (as in "sit") and /i:/ (as in "seat") differ in both length and quality, with the latter being a tense, long vowel.

III. In English, stress can affect both meaning and grammatical category, as seen in words like "record" (noun) and "record" (verb), where the noun is stressed on the second syllable, and the verb on the first.

Which of the following is correct?