R1 cannot form an OSPF neighbor relationship with R3. Which two conditions could cause this? (Choose two.)

OSPF neighbor adjacency requires matching hello and dead interval timers. If these timers differ between R1 and R3, they will not form an adjacency. Additionally, OSPF routers must be in the same area to become full neighbors directly. If R1 and R3 are in different areas, they cannot form a direct neighbor relationship. Incorrect options: OSPF can operate with multiple areas; not all routers need to be in Area 1. DR/BDR roles are for multi-access segments and don't prevent other routers from forming adjacencies. Static routes don't prevent OSPF neighbor formation. EIGRP's administrative distance affects route selection, not OSPF neighbor establishment.