As part of your deployment process, you are configuring your continuous integration (CI) system to build AMIs. You want to build them in an automated manner that is not time constrained and is also cost-efficient. Which method should you use?

Answer options:

A.Attach an Amazon EBS volume to your CI instance, build the root file system of your image on the volume, and use the CreateImage API call to create an AMI out of this volume.
B.Have the CI system launch a new instance, bootstrap the code and apps onto the instance and create an AMI out of it.
C.Upload all contents of the image to Amazon S3 launch the base instance, download all of the contents from Amazon S3 and create the AMI.
D.Have the CI system launch a new spot instance bootstrap the code and apps onto the instance and create an AMI out of it.

Answer – D
The AWS documentation mentions the following
If your organization uses Jenkins software in a CI/CD pipeline, you can add Automation as a post-build step to pre-install application releases into Amazon Machine Images (AMIs). You can also use the Jenkins scheduling feature to call Automation and create your own operating system (OS) patching cadence
Spot instances are an obvious choice because the requirement for the question is "not time constrained" as well as "cost-efficient" solution
For more information on Automation with Jenkins, please visit the link:
http://docs.aws.amazon.com/systems-manager/latest/userguide/automation-jenkins.html
https://wiki.jenkins.io/display/JENKINS/Amazon+EC2+Plugin