SRX devices operate on adefault deny-all policyif no explicit match is found:

If a packet does not match any configuredzone-basedorglobalpolicy, it is implicitly denied.

The traffic is discarded silently by the default security policy (Option A).

Option B:No predefined “safe zone” exists.

Option C:Logging occurs only if explicitly configured; default deny does not automatically log traffic.

Option D:Incorrect, since the firewall defaults to deny, not permit.

Correct Behavior:Traffic is discarded by the default security policy.