GCP Associate Cloud Engineer Practice Question

VPC Network Peering lets two VPC networks exchange private traffic across Google's backbone and, when route exchange is enabled, share their custom routes. However, peering is strictly non-transitive: routes learned from connected services such as Cloud VPN or Cloud Interconnect are not propagated across the peering connection. Therefore, even after you enable import and export of custom routes, analytics-vpc will not learn the on-premises network prefixes that prod-vpc receives through its VPN. To reach the data center, you must create a separate VPN or interconnect that terminates directly in analytics-vpc (or use another supported connectivity pattern). The other options are incorrect because neither additional firewall rules nor Cloud NAT can overcome the absence of transitive routing, and enabling custom route exchange does not make VPC peering transitive.