SSB波束扫描周期可以通过参数NRDUCell.SsbPeriod配置，可在空口上按照既定的Case，gNodeB重复进行多次SSB波束扫描，默认为20ms，那SSB调度周期为（）。

A.SIB1
B.MIB
C.SIB2
D.SIB3

A.SgNB modification request
B.SgNB release request
C.SgNB release request acknowledge
D.SgNB modification request acknowledge

A.QFI
B.5QI
C.RDI
D.RQI