单项选择题

A.Call Drop Rate=eRAB AbnormRel/eRAB Setup Success*100%
B.Call Drop Rate=eRAB AbnormRel/RRC Connection Setup Success*100%
C.Call Drop Rate=eRAB AbnormRel/ eRAB Release Total*100%
D.Call Drop Rate=eRAB AbnormRel// eRAB NormRel*100%