A solutions architect must create a highly available bastion host architecture. The solution needs to be resilient within a single AWS Region and should require only minimal effort to maintain.
What should the solutions architect do to meet these requirements?

A. Create a Network Load Balancer backed by an Auto Scaling group with a UDP listener. B. Create a Network Load Balancer backed by a Spot Fleet with instances in a partition placement group. C. Create a Network Load Balancer backed by the existing servers in different Availability Zones as the target. D. Create a Network Load Balancer backed by an Auto Scaling group with instances in multiple Availability Zones as the target.