You are configuring the networking of a Cloud SQL instance. The only application that connects to this database resides on a Compute Engine VM in the same project as the Cloud SQL instance. The VM and the Cloud SQL instance both use the same VPC network, and both have an external (public) IP address and an internal (private) IP address. You want to improve network security. What should you do?

A. Disable and remove the internal IP address assignment. B. Disable both the external IP address and the internal IP address, and instead rely on Private Google Access. C. Specify an authorized network with the CIDR range of the VM. D. Disable and remove the external IP address assignment.