A company currently hosts a Redshift cluster in AWS. It should ensure that all traffic from and to the Redshift cluster does not go through the Internet for security reasons. Which features can be used to fulfill this requirement in an efficient manner?

Answer options:

A.Enable Amazon Redshift Enhanced VPC Routing.
B.Create a NAT Gateway to route the traffic.
C.Create a NAT Instance to route the traffic.
D.Create a VPN Connection to ensure traffic does not flow through the Internet.

Correct Answer - A
AWS Documentation mentions the following: 
When you use Amazon Redshift Enhanced VPC Routing, Amazon Redshift forces all COPY and UNLOAD traffic between your cluster and your data repositories through your Amazon VPC.If Enhanced VPC Routing is not enabled, Amazon Redshift routes traffic through the Internet, including traffic to other services within the AWS network.
For more information on Redshift Enhanced Routing, please visit the following URL:
https://docs.aws.amazon.com/redshift/latest/mgmt/enhanced-vpc-routing.html