Which of the following is a characteristic of dessert wines?

Dessert wines are specifically characterized by their sweetness, which is primarily due to higher sugar content. This sweetness complements many types of desserts, making them a popular pairing. Typically, dessert wines are rich and flavorful, designed to enhance the taste of sweet courses. They can come from various varietals and may be produced through several methods that concentrate sugars, such as late harvesting, botrytis infection, or passing through freeze processes to create ice wines.

While other characteristics can apply to certain dessert wines, such as some having a high acidity to balance their sweetness, the defining feature that distinguishes them is indeed their sweetness and the tradition of serving them with dessert courses. This pairing tradition enhances the dining experience, making option C the correct answer.