Answer:
grasslands along the Coastal Plains
Explanation:
The climatic conditions of the southern United States near the northern Mexico, which consists mainly of grasslands along the Coastal Plains ecoregion is a unique ecosystem as a result of being affected or closer to the Gulf of Mexico, which made that particular region to have an extensive temperate climate and some form of tropical storms.
Hence, in this case, the correct answer is: The Gulf of Mexico strongly affects the climate of the grasslands along the Coastal Plains.