问题

高层建筑的周围,应设有环形消防车道,当设环形车道有困难时,可沿高层建筑的两个长边设置消防车道,消防车道的宽度不应小于()。尽头式消防车道应设回车道或回车场,回车场尺寸不宜小于(),大型消防车的回车场不宜小于()。
A:4.5m2,15mX15m,18mX18m
B:4m2,15mX15m,18mX18m
C:3.5m2,12mX12m,15mX15m
D:3m2,12mX12m,15mX15m
B:4m2,15mX15m,18mX18m
C:3.5m2,12mX12m,15mX15m
D:3m2,12mX12m,15mX15m
正确答案是: