Final answer:
Saint Lucia is the country with the Roseau, Cal de Sac, Dennery, and Canelles Rivers, contributing to its rich landscapes and agriculture.
Step-by-step explanation:
The country that has the Roseau River, Cal de Sac River, and Dennery River, as well as the Canelles River, is Saint Lucia. This Caribbean island nation boasts a variety of rivers that contribute to its lush landscapes and are critical to its agricultural areas. Each one of these rivers plays a role in transporting water and sediments from the interior to the coasts, similar to how major rivers like the Mekong, Red, and Irrawaddy River in mainland Southeast Asia provide for agricultural abundance and support large populations by creating fertile valleys and deltas.