Which of the following items are required to allow an application deployed on an EC2 instance to write data to a DynamoDB table? Assume that no security keys are allowed to be stored on the EC2 instance.

Answer options:

A.Create an IAM Role that allows write access to the DynamoDB table.
B.Encode the IAM User credentials into the application.
C.Create an IAM User that allows write access to the DynamoDB table.
D.Add an IAM User to a running EC2 instance.
E.Launch an EC2 Instance with the IAM Role included in the launch configuration.

Answer – A and
E.To enable an AWS service to access another one, the most important requirement is to create an appropriate IAM Role and attach that role to the service that needs access.
Option A is CORRECT because it creates the appropriate IAM Role for accessing the DynamoDB table.
Option B is INCORRECT because this is not a best practice, and we need to use IAM Role.
Options C and D are incorrect because IAM Role is preferred and more secure way than IAM User.
Option E is CORRECT because it launches the EC2 instance after attaching the required role.
See the steps below.
1. Create the IAM Role with appropriate permissions
2. Launch an EC2 instance with this role
3. Attach the role to a running EC2
Reference Link: 
http://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles.html
https://aws.amazon.com/about-aws/whats-new/2017/02/new-attach-an-iam-role-to-your-existing-amazon-ec2-instance/