An organization has setup RDS with VPC. The organization wants RDS to be accessible from the
internet. Which of the below mentioned configurations is not required in this scenario?

A.
The organization must enable the parameter in the console which makes the RDS instance
publicly accessible.

B.
The organization must allow access from the internet in the RDS VPC security group,

C.
The organization must setup RDS with the subnet group which has an external IP.

D.
The organization must enable the VPC attributes DNS hostnames and DNS resolution.

Explanation:
A Virtual Private Cloud (VPC) is a virtual network dedicated to the user’s AWS account. It enables
the user to launch AWS resources, such as RDS into a virtual network that the user has defined.
Subnets are segments of a VPC’s IP address range that the user can designate to a group of
VPC resources based on security and operational needs. A DB subnet group is a collection of
subnets (generally private) that the user can create in a VPC and which the user assigns to the
RDS DB instances. A DB subnet group allows the user to specify a particular VPC when creating
DB instances. If the RDS instance is required to be accessible from the internet:
The organization must setup that the RDS instance is enabled with the VPC attributes, DNS
hostnames and DNS resolution.
The organization must enable the parameter in the console which makes the RDS instance
publicly accessible.
The organization must allow access from the internet in the RDS VPC security group.
http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_VPC.html