The question's validity cannot be fully confirmed without the referenced figure. However, based on the definition of an OSPF Area Border Router (ABR), the statement is almost certainly false. An ABR is a router that has at least one interface in the backbone area (Area 0) and at least one interface in a non-backbone area. A router with all its interfaces within a single area (including Area 0) is an internal router, not an ABR. A typical multi-area OSPF network will contain internal routers within each area. Therefore, it is highly improbable that "all routers on the network except RTA are ABRs." For example, any router connected only to other routers within Area 1 would be an internal router, not an ABR.

The other option, True, is incorrect because it contradicts the fundamental definitions of OSPF router types. A network topology where every router except one connects to both the backbone and another area is not a standard or efficient design and would imply that almost no routers are internal to their respective areas.

Huawei HedEx Documentation, HCIA-Datacom V1.0 Training Material (Model H12-811), "OSPF Concepts". This material defines the different types of OSPF routers. It specifies that an ABR "connects the backbone area to a non-backbone area" and has interfaces in at least two different areas, one of which must be Area 0. It also defines an internal router as a device with all interfaces belonging to the same OSPF area.

Cisco Press, "CCNP and CCIE Enterprise Core ENCOR 350-401 Official Cert Guide", Chapter 10, "OSPF". This reputable source defines an ABR as a router with interfaces in more than one OSPF area, which is a standard industry definition applicable to Huawei's implementation.