There is a requirement to host a database server. This server should not be able to connect to the internet except in the case of downloading the required database patches. Which of the following solutions would be the best to satisfy all the above requirements? Choose the correct answer from the options below

Answer options:

A.Set up the database in a private subnet with a security group which only allows outbound traffic.
B.Set up the database in a public subnet with a security group which only allows inbound traffic.
C.Set up the database in a local data center and use a private gateway to connect the application to the database.
D.Set up the database in a private subnet which connects to the Internet via a NAT instance.

Answer – D
This sort of setup as per the aws documentation coincides with Scenario2 of setting up a VPC.For more information on the VPC Scenario for public and private subnets please see the below link:
http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_Scenario2.html