How do Amazon EC2 Auto Scaling groups help achieve high availability for a web application?

How do Amazon EC2 Auto Scaling groups help achieve high availability for a web application?
A . They automatically add more instances across multiple AWS Regions based on global demand of the application
B . They automatically add or replace instances across multiple Availability Zones when the
application needs it
C . They enable the application’s stalk: content to reside closer to end users
D . They are able to distribute incoming requests across a tier of web server instances

View Answer

Answer: B