Final answer:
The phrase 'boundless and bare' in the poem 'Ozymandias' exemplifies situational irony as it contrastingly depicts the transience of power against the lasting desolation, contrary to the king's boastful inscription.
Step-by-step explanation:
Selecting one piece of evidence that supports the situational irony of the poem Ozymandias, the phrase 'boundless and bare' starkly contrasts with the image of a once great kingdom the vanished ruler, Ozymandias, claims to preside over.
The irony lies in the fleeting nature of power and legacy, opposed to the enduring and vast emptiness of the desert sands that have reclaimed the environment. While Ozymandias’ command was once ‘cold’ and mesmeric, what remains now is a desolate landscape, underscoring the impermanence of human achievements and the inexorable passage of time.