Source NAT (Network Address Translation) is used on SRX devices to allow hosts with private IP addresses to access external networks, such as the Internet. The SRX translates the private IP address of the source host into a public IP address before forwarding traffic toward the destination.

It does not translate MAC addresses (Option A).

NAT is unidirectional in this case: it specifically translates private-to-public in the outbound direction, while the reverse (return traffic) is handled automatically through the session table. It is not a bidirectional translation (Option C).

NAT processing occurs as part of the flow module, not limited only to ingress traffic (Option D).

Therefore, the correct statement is that source NAT translates private IP addresses to public IP addresses.