Which part of the meal either preceded or succeeded the cēna in traditional Roman dining?

In traditional Roman dining, the meal structure typically included several courses, and the cēna referred to the main meal, usually enjoyed in the evening. The part of the meal that preceded the cēna is known as gustus. This was essentially an appetizer course, where light foods might be served to stimulate the appetite before the main meal began. It played a significant role in the overall dining experience, setting the stage for the subsequent cēna.

While the other choices refer to different parts of a Roman meal, they follow the main course rather than precede it. Primus mensa refers to the first course, which consists of the main dishes served during the cēna. Secunda mensa represents the second course, often involving desserts or fruits, served after the cēna. Desertum, similarly, relates specifically to the dessert portion, often enjoyed at the end of the meal. Therefore, gustus is the correct answer as it directly precedes the cēna in the traditional Roman dining sequence.