An early model of land use is the concentric ring model of urban form developed by E.W. Burgess. Of the following land uses, which would be closest to the downtown area of the central business district (CBD) according to Burgess' model?
A. Blue-collar residential land useB. A zone of transition containing warehousing and other industrial land uses exists between the downtown area and the residential area.C. White-collar clerical residential land useD. Executive residential land use