The appositive in the above sentence is Jasmine.
The correct option is C.
The appositive is the noun or noun phrase which comes just after the noun or pronoun and renames it. Usually, an appositive is separated from the rest of the sentence with a comma(s). in the above sentence, the phrase 'my sister' is preceded by the name of the sister which is 'Jasmine.' The appositive word 'Jasmine' is also enclosed with two commas which separate it from the whole sentence.
