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

Mad as a march hare

Simile

The correct answer is OPTION 1 - simile.

The figure of speech used in the expression "Mad as a march hare" is simile.

A simile is a figure of speech in which two things are compared using the words "like" or "as." In this case, the person's madness is being compared to the madness of a march hare. This creates a sense of the person's wild and erratic behavior.

The other answer choices are incorrect. Metaphor is a comparison between two things without using the words "like" or "as." Personification is a figure of speech in which inanimate objects are given human qualities. Oxymoron is a figure of speech in which two contradictory terms are used together. None of these devices are used in the expression "Mad as a march hare.".