When using the following AWS services, which should be implemented in multiple Availability Zones for high availability solutions? Choose 2 answers

When using the following AWS services, which should be implemented in multiple Availability Zones for high availability solutions? Choose 2 answers
A . Amazon Dynamo DB
B . Amazon Elastic Compute Cloud (EC2)
C . Amazon Elastic Load Balancing
D . Amazon Simple Notification Service (SNS)
E . Amazon Simple Storage Service {53)

Answer: B, C