Cirrus clouds followed by cirrostratus then altostratus，stratus，and occasionally nimbostratus indicate the approach of a(n)（）.

A.passage of a warm front
B.passage of a cold front
C.winds shifting counterclockwise in the Northern Hemisphere
D.stationary high pressure systems

A.drops and winds become variable
B.rises and winds become gusty
C.drops and winds become gusty
D.rises and winds become variable

A.cold front becoming stationary
B.warm front becoming stationary
C.cold front overtaking a warm front
D.warm front dissipating