What practical limitation was associated with the integrated entertainment system cabinet?

The correct choice highlights a significant constraint in the design of integrated entertainment system cabinets, specifically regarding the size of the picture tube. In traditional integrated systems, the cabinet's design was tightly tailored to house the television components effectively, which meant that larger picture tubes could not be accommodated. This restricted the viewing experience, as consumers often desired larger screens for better picture quality and immersion, which were not possible within the confined space of these cabinets.

While other aspects such as input limitations, lack of digital support, and viewing angles may also be relevant to integrated systems, the specific design of the cabinet presenting a limitation on the picture tube size is a key consideration. As technology progressed, it became clear that larger screen sizes were necessary to meet consumer demand for enhanced viewing experiences, making this limitation particularly significant in understanding the evolution of entertainment systems.