Which statement about the OSPF incremental SPF feature is true?
A . Routers with incremental SPF enabled and routers with incremental SPF not enabled cannot function in the same domain
B . If type 1 or type 2 LSA changes occur in the calculating router itself, the full SPF is performed even when OSPF incremental SPF is enabled.
C . The OSPF incremental SPF features allows for the system to recompute only the affected part of the tree when type 2 or type 5 LSA changes occur.
D . If the incremental SPF feature is enabled the entire SPT must be recomputed even the tree remains unchanged inside of the OSPF area
Answer: B