A. The output lists nothing unless 10.100.0.0 has been configured as a summary rou te using the area range command.
B. If 10.100.0.0 is a subnet in area 0, the output lists one Type 3 LSA, specifically the LSA with the lower metric when comparing ABR1's and ABR2's LSA for 10.100.0.0.
C. If 10.100.0.0 is a subnet in area 0, the output lists two Type 3 LSAs, one each created by BR1 and ABR2.
D. None, because the Type 3 LSAs would exist only in the ABR's LSDBs.