Final answer:
The correct sentence with proper punctuation is 'Mom's brownies never remain in her kitchen very long' and the possessive personal pronoun is 'her'.
Step-by-step explanation:
The sentence that is correctly punctuated is B. Mom's brownies never remain in her kitchen very long. The possessive personal pronoun in this sentence is C. her.
The apostrophe in "Mom's" indicates that the brownies belong to Mom, therefore it is a possessive noun, not a possessive pronoun. Possessive pronouns include words like 'his', 'hers', 'theirs', and in this case, 'her', which does not require an apostrophe as it already shows possession.