Halides of alkaline earth metals form hydrates such as `MgCl_(2).6H_(2)O,CaCl_(2).6 H_(2)O,BaCl_(2).2H_(2)O` and `SrCl_(2).2H_(2)O`. This shows that halides of group 2 elements `:`
A. are hygroscopic in nature
B. act as dehydrating agents
C. can absorbs moisture from air
D. all of the above