Which of the following is an example of a perennial ground cover plant?

Creeping phlox is classified as a perennial ground cover plant because it grows back year after year and forms a dense mat of foliage that helps to suppress weeds. This plant is known for its vibrant flowers in spring and is commonly used in landscaping for erosion control, to provide color in garden beds, and to create attractive ground surfaces.

In contrast, the other options are not suitable examples of perennial ground cover. Petunia is typically treated as an annual in many climates, meaning it completes its life cycle within a single growing season. Roses, while they can be perennials, are primarily upright shrubs rather than ground cover plants. Daffodils, although they are perennials, grow upright and do not spread across the ground in a way that would classify them as ground cover. Thus, creeping phlox stands out as the only appropriate choice among the options provided.