Create 2 Virtual Private Gateways and configure one with each VPC.
Create 2 Internet Gateways, and attach one to each VPC.
Create a VPC Peering connection between both VPCs.
Create one EC2 instance in each subnet, assign Elastic IPs to both instances, and configure a set up Site-to-Site VPN connection between both EC2 instances.
Explanations:
Creating two Virtual Private Gateways does not facilitate communication between the two VPCs directly; each gateway is meant for a single VPC, and they do not connect VPCs to each other.
Internet Gateways are used to enable internet access for resources in a VPC but do not provide a way to connect two different VPCs. Thus, this option does not solve the problem of connecting the two subnets.
A VPC Peering connection allows for direct network routing between two VPCs, enabling instances in both subnets to communicate with each other as if they were in the same network. This is the appropriate solution for connecting the two specified subnets.
Setting up EC2 instances with Elastic IPs and configuring a Site-to-Site VPN connection is a more complex solution and not necessary for simple communication between the two subnets. It also does not directly connect the subnets as required.
I rank that the answer is:
Create a VPC Peering connection between both VPCs.