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 Simple Storage Service
B . Amazon Elastic Load Balancing
C . Amazon Elastic Compute Cloud
D . Amazon Simple Notification Service
E . Amazon DynamoDB

Answer: B,C