The following excerpt is from a short story about a young girl's adventure in a magical forest:

As Emily stepped deeper into the woods, the air grew thicker with an enchanting mist. Trees taller than skyscrapers loomed overhead, their leaves shimmering in a vibrant array of colors. Birds with iridescent feathers flitted about, singing melodies that echoed the wonder of this hidden world. But as she pressed on, the uplifting sounds faded, replaced by a low, rumbling growl that sent shivers down her spine. Emily froze, her heart racing, and peered into the shadowy underbrush. What was lurking just beyond her vision?

Understanding the structure of this passage helps the reader to anticipate what might happen next. The author uses descriptive imagery and builds tension to enhance the narrative. Which of the following best describes the primary structure of this excerpt?