Final answer:
The inner zone in the theory of protection is normally referenced as the most secure area. In urban planning, the innermost zone corresponds to the inner city, containing centralized economic and administrative functions and is not always the safest area.
Step-by-step explanation:
The inner zone in the theory of protection refers to the most secure area within a protective model. In the context of urban planning and the concentric zone model, the innermost zone (Zone 1) corresponds to the inner city, which includes the central business district and is usually the most densely developed part. This is not necessarily the 'most secure' area in terms of safety, but it is where important economic and administrative functions are concentrated. As you move outward to zones like Zone B in the concentric zone model, the area is likely to house the city's industrial center. This model, presented in classic urban sociology, depicts a series of concentric circles emanating from the central city to the exurbs.