Explanation
Use Cloudf rant distribution for distributing the heavy reads for your application. You can create a zone apex record to point to the Cloudfront distribution.
You can control how long your objects stay in a CloudFront cache before CloudFront forwards another request to your origin. Reducing the duration allows you to serve dynamic content. Increasing the duration means your users get better performance because your objects are more likely to be served directly from the edge cache. A longer duration also reduces the load on your origin.
For more information on Cloudfront object expiration, please visit the below URL:
* http://docs.aws.amazon.com/AmazonCloudFrant/latest/DeveloperGuide/Cxpiration.html

Even if you're careful to stay within the free tier, it's a good idea to create a billing alarm to notify you if you exceed the limits of the free tier. Billing alarms can help to protect you against unknowingly accruing charges if you inadvertently use a service outside of the free tier or if traffic exceeds your expectations. http://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/free- tier-alarms.html

This is the complete list of Intrinsic Functions...: Fn::Base64, Fn::And, Fn::Equals, Fn::If, Fn::Not, Fn::Or,
Fn::FindInMap, Fn::GetAtt, Fn::GetAZs, Fn::Join, Fn::Select, Ref
Reference:
http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference.html

Explanation
Option B makes sense because maybe the max servers is low hence the application cannot handle the peak load.
Option D helps in ensuring Autoscaling can scale the group on the right metrics.
For more information on Autoscaling health checks, please refer to the below document link: from AWS
* http://docs.aws.amazon.com/autoscaling/latest/userguide/healthcheck.html