What factors should be considered when troubleshooting FortiGuard issues? (Select all that apply)

What factors should be considered when troubleshooting FortiGuard issues? (Select all that apply)
A . DNS resolution for FortiGuard servers
B . Active FortiGuard subscription status
C . Firewall rules that may block FortiGuard updates
D . Time synchronization between FortiGate and NTP servers

Answer: ABC