Final answer:
Complementary distribution is the pattern that proves the two segments are allophones of one phoneme.
Step-by-step explanation:
The pattern that proves to be evidence that the two segments we are considering are allophones of one phoneme is a) Complementary distribution. Complementary distribution occurs when two allophones appear in mutually exclusive phonetic environments, meaning that one allophone is used in certain contexts and the other in different contexts. For example, in English, the sounds /p/ and /b/ are allophones of the phoneme /p/ depending on their position in a word. /p/ is used at the beginning of a word, while /b/ is used in the middle or end of a word. This shows complementary distribution and provides evidence that they are allophones of the same phoneme.