The question revolves around enabling IoT devices to connect to an AWS application endpoint without DNS resolution, using an Amazon EC2 Auto Scaling solution. The key requirements are the inability of IoT devices to support DNS resolution and the need for a cost-effective solution. Option A suggests using an ALB-type target group for an NLB, which is not a standard or cost-effective approach since ALB and NLB serve different purposes and mixing them unnecessarily increases complexity and cost. Option B proposes using AWS Global Accelerator with an ALB endpoint. While AWS Global Accelerator can provide static IP addresses, using it with an ALB does not directly address the DNS resolution issue and may not be the most cost-effective solution. Option C recommends using an NLB directly, which is a straightforward and cost-effective solution. NLBs provide static IP addresses that IoT devices can connect to without needing DNS resolution, and they are designed to handle high volumes of traffic efficiently. Option D suggests using AWS Global Accelerator with an NLB endpoint. While this would work, it introduces additional costs and complexity that are not necessary for the given requirements. Therefore, the most cost-effective and straightforward solution is to use an NLB directly, as it meets all the requirements without unnecessary complexity or cost.