An engineer combines Elastic Load Balancing with Amazon EC2 Auto Scaling for a fluctuating web application. Which statement best describes how these two services work together?
- AThe load balancer decides how many instances to run, and Auto Scaling caches static content close to users at edge locations worldwide
- BThe load balancer stores the application data on durable volumes, and Auto Scaling encrypts every request before it reaches an instance
- CAuto Scaling provides the private network for the instances, and the load balancer resolves the application domain name to instance addresses
- DAuto Scaling adjusts the number of instances with demand, and the load balancer spreads incoming traffic across the healthy instances Correct
Why A is wrong: Auto Scaling sets the instance count rather than caching content, so this swaps the two roles and adds a caching task neither service performs here.
Why B is wrong: Load balancers do not store application data and Auto Scaling does not encrypt requests, so this misstates the purpose of both services.
Why C is wrong: A VPC provides the network and Route 53 resolves domain names, so neither described task belongs to Auto Scaling or the load balancer.
Why D is correct: Auto Scaling changes how many instances run as demand varies, while the load balancer distributes requests across whichever healthy instances exist.