Which of the following describes the essential aspect of a digital event for attendees?

The essential aspect of a digital event for attendees is the connection between online and physical audiences. This connection ensures that participants, whether they are physically present or attending virtually, can engage with one another and share their experiences in real time. By fostering interaction among both groups, digital events are able to create a more inclusive environment that enhances the overall experience for all attendees. This aspect is crucial for networking, collaboration, and building community, which are often primary objectives of attending any type of event.

Other choices, while they may have their own importance, do not capture this critical need for connectivity and communal interaction that defines a successful digital event experience. Low-cost execution may benefit the organizers but does not enhance the attendee experience itself. The incorporation of promotional materials is relevant for marketing purposes but doesn't directly relate to the core attendee experience. Focusing solely on digital content can overlook the importance of creating engagement opportunities that include both online and in-person participants. Thus, option C uniquely encapsulates the essence of what makes a digital event valuable for attendees.