An Organization Is Setting Up a Backup and Restore System

An organization is setting up a backup and restore system in AWS of their in premise system. The organization needs High Availability(HA) and Disaster Recovery(DR) but is okay to have a longer recovery time to save costs. Which of the below mentioned setup options helps achieve the objective of cost saving as well as DR in the most effective way?

A) Setup pre-configured servers and create AMIs. Use EIP and Route 53 to quickly switch over to AWS from in premise.
B) Setup the backup data on S3 and transfer data to S3 regularly using the storage gateway.
C) Setup a small instance with AutoScaling; in case of DR start diverting all the load to AWS from on premise.
D) Replicate on premise DB to EC2 at regular intervals and setup a scenario similar to the pilot light.