Fully Managed Data Warehouse Services

Correct Answer - B.

Amazon Redshift is a fully managed, petabyte-scale data warehouse service.

Option A is INCORRECT because Amazon Athena is used to query data and analyze big data in S3.

Option C is INCORRECT because Amazon CloudWatch is used to monitor AWS resources, collect metrics, configure alarms, etc.

Option D is INCORRECT because there is no such AWS service.

The AWS service that is suitable to be used as a fully managed data warehouse is Amazon RedShift.

Amazon RedShift is a fully managed data warehouse service that is designed to handle petabyte-scale data warehouses. It is a cloud-based data warehousing solution that is built for large-scale analytics workloads. It is optimized for high-performance querying and analysis of structured data using SQL, and it can handle both structured and unstructured data. RedShift is a columnar storage database that uses massively parallel processing (MPP) to distribute workloads across multiple nodes, enabling it to handle large volumes of data with ease.

RedShift also provides a range of features to optimize performance, including automatic compression, data distribution, and query optimization. Additionally, RedShift supports a variety of standard SQL clients and JDBC/ODBC drivers, making it easy to connect and work with from your existing tools and applications.

Amazon Athena, on the other hand, is a serverless interactive query service that enables users to analyze data stored in Amazon S3 using standard SQL. It is ideal for ad-hoc querying of data, and it doesn't require users to provision or manage any infrastructure. It is not a data warehouse service, but rather a query service that can be used to analyze data stored in S3.

Amazon CloudWatch is a monitoring and management service for AWS resources, and it is not a data warehouse service.

Amazon Warehouse is not a valid AWS service and does not exist.

Therefore, the correct answer is B. Amazon RedShift.