Final answer:
The literary device in the phrase 'sweet pertater pie' is c) alliteration, due to the repeated 'p' sound.
Step-by-step explanation:
The literary device used in the phrase "sweet pertater pie" is c) alliteration. Alliteration is reflected in the repetition of the initial consonant sound 'p' in 'sweet pertater pie'. This literary device often provides rhythm and musicality to the phrase, making it more engaging and memorable.
Alliteration is commonly found in poetry, but can also be employed effectively in prose to emphasize a particular mood or theme.