Based on the provided statements, Species C would most likely be classified as an invasive species in the United States. Invasive species are characterized by their ability to thrive in a new environment, often outcompeting native species and causing ecological harm, which aligns with Species C's description of growing up to a foot per day, smothering low-growing plants, killing trees, and lacking natural predators.
The other species mentioned do not exhibit the same level of harmful ecological impact:
- Species A is considered a weed but does not grow uncontrollably.
- Species B is farmed for its pollination capabilities and does not appear to have a damaging effect on the environment.
- Species D is used as a biological control against an invasive plant and does not affect native plants, indicating it is not invasive itself.
Thus, Species C stands out as the one most likely to be deemed invasive.