有一空调房间采用圆形散流器送风，按等温射流计算求出室内平均风速为0.25m/s，则夏送冷风，冬送热风时室内平均风速分别为( )
A、0.25m/s，0.25m/s
B、0.25m/s，0.2m/s
C、0.3m/s，0.25m/s
D、0.3m/s，0.2m/s