What is an Auto Scaling group?

A. It is a group of ELBs that are used to add instances from various regions.
B. It is a logical grouping of EC2 instances that share similar characteristics for scaling and man-agement.
C. It is a collection of EC2 instance launch parameters with different characteristics for scaling and management.
D. It is a group of launch configurations for Elastic load balancers in the same region.