Final answer:
In Shakespeare's 'A Midsummer Night's Dream,' Pyramus kills himself because he wrongly thinks that Thisby has been killed by a lion, and the correct answer is option D.
Step-by-step explanation:
In the play-within-the-play of William Shakespeare's A Midsummer Night's Dream, Pyramus kills himself because he mistakenly believes that Thisby has been killed by a lion. This tragic misunderstanding mirrors the thematic element of mistaken identity and the consequences of assumption that run throughout the play.
The correct answer to the question is option D, "He believes that Thisby has been killed by a lion." This scenario is reminiscent of other tragic plays by Shakespeare where characters make fatal decisions based on false perceptions, such as the misguided actions leading to the deaths of Romeo and Juliet.