The term "rising action" is a term which only has application to a critical device called Freytag's Pyramid, in which it refers to the action in Act 2 of a typical five-act play, and by "typical" I here mean a Shakespearean Tragedy, since the Freytag Pyramid doesn't always fit the histories and comedies. Since the Prologue of Romeo and Juliet is not a five-act play (it is in fact a Sonnet), the Freytag Pyramid and therefore the term "rising action" cannot apply to it. You could probably see that coming when you heard it was a prologue, since there is never any action of any kind in a Prologue (if there were, it would be an "Induction", as in The Taming of the Shrew).
The deaths of Romeo and Juliet
The deaths of Romeo and Juliet.
(Prolouge line #. )
The narrator
framework
The deaths of Romeo and Juliet
The major plot element spoiled in the prologue of Romeo and Juliet is the tragic ending of the play, where the two young lovers, Romeo and Juliet, ultimately die.
Romeo and Juliet
The deaths of Romeo and Juliet.
(Prolouge line #. )
The narrator
The line from the prologue of Romeo and Juliet that foreshadows the tragic ending of the play is "A pair of star-crossed lovers take their life."
The Prologue, then Sampson, then Gregory.
framework
As dictated in the prologue "Is now the two hours' traffic of our stage". Romeo and Juliet ran for two hours.
Star crossed!
It is telling you what is going to happen in the story.