Which is an example of dramatic irony in act v, scene iii of Romeo and Juliet?

Which is an example of dramatic irony in act v, scene iii of Romeo and Juliet?

a.romeo thought Juliet was dead when he poisoned himself, but the audience knew she was alive.

b.balthasar agreed to deliver Romeo’s letter, and the audience knew the contents of the letter.

c.juliet knew Romeo was dead when she awakened, and the audience knew that she was correct.

d.friar Laurence thought his plan would help Romeo and Juliet, but the audience knew he had evil intentions.