Final answer:
Luxembourg is the country that features the hilly, forested Oesling region in the north and the fertile, agrarian Gutland area in the south.
Step-by-step explanation:
The country with the Oesling region in the north, and Gutland in the south is Luxembourg. The Oesling region is part of the Ardennes and covers the northern third of Luxembourg, characterized by its hilly terrain and forested landscapes.
On the other hand, Gutland covers the southern two-thirds of the country and is known for its more fertile and flat lands, which are ideal for agriculture and home to most of Luxembourg's population.