Final answer:
Interactivity did not guarantee radio's survival alongside television; rather, adaptability, portability, and localized content played crucial roles in radio's continued relevance.
Step-by-step explanation:
The factor that did not guarantee radio's survival alongside television is Interactivity. When television emerged, radio needed to find its niche to remain relevant. Important factors for radio's endurance included its Adaptability, like changing formats and content; its Portability, allowing people to listen on the go, and its Localized Content, providing specific programs for local audiences. Interactivity, while important in today's media landscape, was not the key element that ensured radio's survival during television's rise. Instead, television became the medium known for greater interactivity, as the audience could both hear and see the content.