The Snowflake Cloud Services layer is responsible for coordinating and managing the overall system. According to Snowflake documentation and the community consensus (100% agreement with upvoted comments), this layer handles metadata management (A) and query parsing/optimization (E). Option B (Computing the data) is performed by the Virtual Warehouse layer, not Cloud Services. Option C (Maintaining Availability Zones) is infrastructure management handled by the cloud provider, not Snowflake's Cloud Services. Option D (Infrastructure security) is also managed by the cloud provider, not Snowflake's Cloud Services layer, which focuses on application-level security and coordination.