A user has created an ELB with the availability zone US-East-1. The user wants to add more zones to ELB to achieve High Availability. How can the user add more zones to the existing ELB?

A. It is not possible to add more zones to the existing ELB
B. The only option is to launch instances in different zones and add to ELB
C. The user should stop the ELB and add zones and instances as required
D. The user can add zones on the fly from the AWS console