Figurative Language in Urban Imagery

Read the following lines from a poem:

"The city awakens, an orchestra of sound, / Each horn a cry, a clarion call to the dawn; / Beneath the concrete, hearts beat in unison, / Where dreams march in time to the rhythm of life."

In this excerpt, the poet uses various forms of figurative language to convey the vibrancy and complexity of urban life. Which of the following options best identifies a specific use of figurative language that enhances the imagery presented?