Refertotheexhibit.Whichoptioncorrectlydescribestheorderofsignalingandcall processingeventswhenabranchemployeecallsheadquarters?()A.P，S，T，UB.U，T，S，PC.S，U，P，TD.P，U，S，TE.S，P，U，TF.S，P，T，U
题目
Refertotheexhibit.Whichoptioncorrectlydescribestheorderofsignalingandcall processingeventswhenabranchemployeecallsheadquarters?()
A.P，S，T，U
B.U，T，S，P
C.S，U，P，T
D.P，U，S，T
E.S，P，U，T
F.S，P，T，U