Under the AWS shared responsibility model:

Customer Responsibilities:

• Configuration of security groups (B) - Customers are responsible for configuring security groups, which act as virtual firewalls for EC2 instances
• Encryption of customer data on AWS (C) - Customers are responsible for implementing data encryption for their data stored on AWS services

AWS Responsibilities:

• Physical security of AWS facilities (A) - AWS is responsible for the physical security of data centers
• Management of AWS Lambda infrastructure (D) - AWS manages the underlying infrastructure for serverless services like Lambda
• Management of network throughput of each AWS Region (E) - AWS manages the network infrastructure and throughput between regions

The shared responsibility model divides security responsibilities where AWS is responsible for security of the cloud (infrastructure), while customers are responsible for security in the cloud (their data, applications, and configurations).