You Have Written an Application That Uses the Elastic Load

You have written an application that uses the Elastic Load Balancing service to spread traffic to several web servers. Your users complain that they are sometimes forced to login again in the middle of using your application, after they have already logged in. This is not behavior you have designed. What is a possible solution to prevent this happening?

A) Use instance memory to save session state.
B) Use instance storage to save session state.
C) Use EBS to save session state
D) Use ElastiCache to save session state.
E) Use Glacier to save session slate.