What AWS services should be used meet these requirements?

A read only news reporting site with a combined web and application tier and a database tier that receives large
and unpredictable traffic demands must be able to respond to these traffic fluctuations automatically.
What AWS services should be used meet these requirements?

A.
Stateless instances for the web and application tier synchronized using ElastiCache Memcached in an
autoscaimg group monitored with CloudWatch and RDS with read replicas.

B.
Stateful instances for the web and application tier in an autoscaling group monitored with CloudWatch and
RDS with read replicas.

C.
Stateful instances for the web and application tier in an autoscaling group monitored with CloudWatch. And
multi-AZ RDS.

D.
Stateless instances for the web and application tier synchronized using ElastiCache Memcached in an
autoscaling group monitored with CloudWatch and multi-AZ RDS.