The primary purpose of configuring a main link between the devices is to synchronize session information so that if one unit fails, the other can continue processing traffic without dropping active sessions.
A).To have both sessions and configuration synchronization in layer 2.This is incorrect because FGSP is used for session synchronization, not configuration synchronization.
B).To load balance both sessions and configuration synchronization between layer 2 and 3.FGSP does not perform load balancing and is not used for configuration synchronization.
C).To have only configuration synchronization in layer 3.The main link is not used solely for configuration synchronization.
D).To have both sessions and configuration synchronization in layer 3.The main link in an FGSP setup is indeed used to synchronize session information across the devices, and it operates at layer 3 since it uses IP addresses to establish the peering.

Option B is correct because each FortiGate in the Security Fabric can send logs to FortiAnalyzer for centralized logging and analysis12. This allows you to monitor and manage the entire Security Fabric from a single console and view aggregated reports and dashboards.
Option A is incorrect because the root FortiGate is not the only device that can send logs to FortiAnalyzer. The root FortiGate is the device that initiates the Security Fabric and acts as the central point of contact for other FortiGate devices3. However, it does not have to be the only log source for FortiAnalyzer.
Option C is incorrect because the FortiGate devices performing NAT or UTM are not the only devices that can send logs to FortiAnalyzer. These devices can perform additional security functions on the traffic that passes through them, such as firewall, antivirus, web filtering, etc4. However, they are not the only devices that generate logs in the Security Fabric.
Option D is incorrect because the last FortiGate that handled a session in the Security Fabric is not the only device that can send logs to FortiAnalyzer. The last FortiGate is the device that terminates the session and applies the final security policy5. However, it does not have to be the only device that reports the session information to FortiAnalyzer. Reference: =
1: Security Fabric - Fortinet Documentation1
2: FortiAnalyzer Demo6
3: Security Fabric topology
4: Security Fabric UTM features
5: Security Fabric session handling

From the partial OSPF (Open Shortest Path First) configuration output:
B: The router sends grace LSAs before it restarts: This is implied by the command 'set restart-mode graceful- restart'. When OSPF is configured with graceful restart, the router sends grace LSAs (Link State Advertisements) to inform its neighbors that it is restarting, allowing for a seamless transition without recalculating routes.
Fortinet documentation on OSPF configuration clearly states that enabling graceful restart mode allows the router to maintain its adjacencies and routes during a brief restart period.

In IKE version 2, not all packets are fragmentable. Only certain messages within the IKE negotiation process can be fragmented. Additionally, there is a limit to the number of fragments that IKE version 2 can handle, which is 128. This is specified in the Fortinet documentation and ensures that the IKE negotiation process can proceed even in networks that have issues with large packets. The reassembly timeout and the layer at which fragmentation occurs are not specified in this context within Fortinet documentation.

Option D is the correct answer because it specifically blocks access to the website "www.eicar.org" using TCP protocol and HTTP service, which are commonly used for web browsing. The other options either use the wrong protocol (UDP), the wrong service (DNS or SSL), or the wrong pattern ("eicar" instead of
"www.eicar.org"). References := Configuring custom signatures | FortiGate / FortiOS 7.4.0 - Fortinet Document Library, section "Signature to block access to example.com".