Correct answer - "Deploy in a VPC and assign a Security Group" : Lambda functions by default do
not have VPC connectivity. You need to enable VPC connectivity and assign a Security Group to
your instance to allow them to talk directly to your RDS instances.
"Assign an IAM role" - This will not enable Lambda to have connectivity to RDS in a private VPC,
although this could be helpful in authenticating to the database engine if it supports RDS IAM
authentication.
"Use Environment variables to pass in the RDS connection string" - You can utilize environment
variables but you will still need access to RDS
"Use aliases" - An alias allows you to point it to a version of your choice without the caller
having to know