From the given options, select the Figure of Speech (Poetic Device) used in the expression:

O death! where is thy sting?

Apostrophe

The figure of speech used in the expression "O death! where is thy sting?" is OPTION 4  Apostrophe.

Apostrophe is a figure of speech in which the speaker addresses an absent or inanimate object. In this case, the speaker is addressing death, which is an inanimate object. This creates a sense of urgency and emotion, as the speaker is challenging death.

The other answer choices are incorrect. Simile is a comparison between two things using the words "like" or "as." Metaphor is a comparison between two things without using the words "like" or "as." Pun is a play on words. None of these devices are used in the expression "O death! where is thy sting?".