InAIX5Landlater,theoperatingsystemsupportsthe／procfilesystem.Whatwouldbethebestdescriptionofthe／procfilesystem?()

A.Itisapseudofilesystemthatmapsprocessesandkerneldatastructurestocorrespondingfiles.

B.ItisaJFSmountedfilesystemthatprovidesanexactrepresentationofwhatishappeningtoaprocesatasingleanddiscretepointoftime.

C.ItisaJFSmountedfilesystemthatmapsprocessesandread-onlyfilesrelatedtotheseprocesses.

D.Itisapseudofilesystemthatcontainsdatathatrepresentsthestateoftheparentprocesses（butnottheirthreads）inasystem.