Which option best describes a promotional feature of the Sonic mobile app?

The promotional feature of the Sonic mobile app is best represented by the ability to order ahead. This feature enables customers to place their orders before arriving at the Sonic location, which enhances convenience and saves time. By utilizing the order ahead option, users can skip long lines and ensure their food is prepared and ready for pickup upon arrival, creating a more efficient and enjoyable experience.

This time-saving aspect makes the order ahead feature particularly appealing as a promotional tool, especially for busy customers looking to maximize their time. In contrast, while subscription services, free delivery, and social media integration may exist within various applications, the specific advantage of seamless order placement ahead of time stands out as a core promotional element that highlights the Sonic app's convenience and customer-oriented design.