English example sentences with "phoneme"

Say which of the following groups of phonemes contains one which is not an English phoneme.

That sound does not exist in the language as a separate phoneme.

The sound exists in the language only as an allophone of the phoneme /t/.

In this language, the phoneme /b/ is pronounced [p] when it occurs at the end of a word.

The two phones, which initially were allophones of a single phoneme, became distinct phonemes as a result of these sound changes.

The voiced retroflex flap appears as a phoneme in Bengali.

I do not really prefer English text. The badly distorted grapheme-to-phoneme relationships are really ugly. Silent letters, double letters, distorted diphthongs, awkward letter sequences, mumbled syllables, etc. are really disorganization. Because, being a linguist, I can compare with other languages, I am aware of these things.