You work as a System Administrator for a company. Your team has launched an Autoscaling Group using launch configuration, and the set of underlying instances are in the running state. There is a requirement to change the Instance type for the underlying instances and ensure that the Autoscaling group launches the Instances with the new Instance type. How would you make these changes? (Select TWO)

Answer options:

A.Create a new launch template.
B.Replace a launch configuration with a launch template using Amazon EC2 Auto Scaling console.
C.Modify the existing launch configuration.
D.Update the Autoscaling Group with the modified launch configuration usingAmazon EC2 Auto Scaling console.

Correct Answers: A and B
This is given in the AWS Documentation.
Instance Types can be changed by creating a new launch configuration and updating the auto-scaling group or by replacing the launch configuration with a launch template.
Based on the question, to edit an Auto Scaling group that has an existing launch configuration, you have the option of replacing the launch configuration with a launch template. Before you can replace a launch configuration in an Auto Scaling group, you must first create your launch template. 
Options C and D are incorrect because you cannot modify the existing launch configuration. You have to create a new launch configuration.
For more information on the Launch configuration, please refer to the below URL-
https://docs.aws.amazon.com/autoscaling/ec2/userguide/LaunchConfiguration.html
https://docs.aws.amazon.com/autoscaling/ec2/userguide/replace-launch-config.html