Final answer:
The term 'ceremony' best fits the context of a family gathering due to its association with traditions and rituals that are acknowledged across various cultures and religions, making it the suitable answer to complete the sentence.
Step-by-step explanation:
Understanding the context of family gatherings is crucial when choosing the correct word to complete the sentence. A family gathering could encompass various activities, but the term that best fits with the common elements of universality and solemnity associated with such occasions is often ceremony. A ceremony may involve traditions and rituals that are part of a culture or religion. For instance, this could be a much-celebrated ceremony itself, such as a baptism or confirmation in a church, or a funeral service. Rituals performed during ceremonies have a concrete purpose and are deeply symbolic, while the concept of ceremony can also be seen in social practices such as a marriage, where an exchange of symbolic foods or activities may occur, binding families together. In contrast, a convention is typically a large gathering often based around a specific theme or professional subject matter, and an event is arguably more general and could apply to any scheduled occurrence. Therefore, option A) Ceremony is the best answer to the question.