When troubleshooting the network, you find that there may be a problem with the OSPF configuration on a certain router, but when you log in to the network device to check the OSPF configuration, you find that the OSPF and BFD linkage configuration is also wrong, so you modify the configuration of OSPF and BFD.
The network troubleshooting method belongs to which one of the following?
A . Block method
B . Comparative configuration method
C . Segmentation method
D . Bottom-up approach
Answer: A