单项选择题
OnanAironetcard，LED0andLED1areblinkingalternately.Whatdoesthisindicate？（）
A.TheAironetcardisinpowersavemode.
B.TheAironetcardislookingforanetworkassociation.
C.TheAironetcardisjoinedtoanetwork，butthereisnonetworkactivity.
D.TheAironetcardisjoinedtoanetwork，andthereisnetworkactivity.