How can the company use Route 53 to point to the load balancer in the MOST cost-effective and efficient manner?
Create an Amazon EC2 proxy in Account A that forwards requests to Account B.
Create a load balancer in Account A that points to the load balancer in Account B.
Create a CNAME record in Account A pointing to an alias record for the load balancer in Account B.
Create an alias record in Account A pointing to the DNS name for the load balancer in Account B.
Explanations:
An EC2 proxy in Account A would introduce unnecessary complexity and cost by routing traffic through an additional EC2 instance. This solution is inefficient.
Creating a load balancer in Account A would incur additional costs and complexity. The goal is to point to an existing load balancer in Account B, not replicate it.
A CNAME record cannot be used at the apex of a domain (i.e., for a zone’s root). It also wouldn’t take advantage of the Route 53 alias record functionality.
An alias record in Route 53 is the most efficient and cost-effective method, as it allows pointing directly to the DNS name of the load balancer in Account B.
I suspect that the answer is:
Create an alias record in Account A pointing to the DNS name for the load balancer in Account B.