Final answer:
Dramatic irony in Act V of Shakespeare's Romeo and Juliet originates from the audience knowing Juliet is alive while Romeo believes she is dead, leading to the tragic conclusion of both lovers taking their own lives.
Step-by-step explanation:
The lines in Act V of Shakespeare's Romeo and Juliet that create dramatic irony refer to the scene when Romeo finds Juliet in the tomb and, believing she is dead, kills himself. The audience, however, is aware that Juliet is not dead but merely in a deep sleep due to the potion she has taken. When Juliet awakens and discovers that Romeo has killed himself in despair, not knowing she is still alive, she then takes her own life. This situation is steeped in dramatic irony because the audience is privy to Juliet's plan and knows she is alive, yet watches helplessly as Romeo makes his tragic error.