Final answer:
The cheese crowned as 'the king of cheeses' in 1815 is Camembert. It is a creamy cow's milk cheese from Normandy, France, and remains popular globally.
Step-by-step explanation:
In a competition in 1815, the cheese that was crowned le roi des fromages, which translates to "the king of cheeses," is Camembert (option d). It is a soft, creamy, surface-ripened cow's milk cheese that originated in the northern region of Normandy, France. Despite the competition happening in the early 19th century, Camembert has remained a very popular cheese around the world, often appreciated for its rich and buttery flavor.