A. The summary-address command is used only for summarizing prefixes between areas.
B. The summary route is visible only in the OSPF database, not in the routing table.
C. There is no route for a subnet inside 10.0.0.0/8, so the summary route is not generated.
D. The summary route is not visible on this router, but it is visible on other OSPF routers in the same area.