单项选择题
A.ACTIVATE DEFAULT EPS BEARER CONTEXT ACCEPTB.DEACTIVAT……
EPS缺省承载建立成功的触发消息为()
A.ACTIVATE DEFAULT EPS BEARER CONTEXT ACCEPT
B.DEACTIVATE EPS BEARER CONTEXT REQUEST
C.ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST
D.DEACTIVATE EPS BEARER CONTEXT ACCEPT