A VPC has existing zonal NAT gateways in Availability Zones A and B. Private workers in zone B currently send outbound internet traffic through the NAT gateway in zone A, incurring cross-AZ data transfer. Both gateways must remain deployed for other workloads. Which change best reduces this traffic cost while preserving private worker addressing?

1. Keep zone-B workers routed through zone A and add more workers in zone B.
2. Route the zone-B workers' internet-bound traffic to the existing NAT gateway in zone B.
3. Assign public IPv4 addresses to the workers and keep the private-subnet route unchanged.
4. Use an S3 gateway endpoint as the default route for all arbitrary internet destinations.