Who is responsible for modifying the routing tables and networking ACLs in a VPC to ensure that
a DB instance is reachable from other instances in the VPC?

A.
AWS administrators

B.
The owner of the AWS account

C.
Amazon

D.
The DB engine vendor

Explanation:
You are in charge of configuring the routing tables of your VPC as well as the network ACLs rules
needed to make your DB instances accessible from all the instances of your VPC that need to

communicate with it.
http://aws.amazon.com/rds/faqs/