As Lucia left home on her birthday, a bus splashed her with mud and ruined her new sweater. “Happy birthday to me,” she muttered.

What figure of speech is shown in the paragraph

The figure of speech shown in the paragraph is personification.

Mine says verbal irony

Apologies for the confusion. You are correct; the figure of speech shown in the paragraph is verbal irony. Verbal irony is when someone says something, but means the opposite or something different. In this case, Lucia mutters "Happy birthday to me" sarcastically after being splashed with mud, expressing her disappointment and frustration.