The correct answer is B. Cloud Composer. Cloud Composer is a cloud-native service designed for workflow orchestration, making it ideal for managing data pipelines in a hybrid cloud environment. It leverages Apache Airflow to create, schedule, and monitor workflows across multiple cloud services and on-premises systems, ensuring seamless integration with Google Cloud and third-party tools.

• A. Cloud Dataproc: While excellent for running Apache Spark and Hadoop clusters for big data analytics, it's not tailored for workflow orchestration.
• C. Cloud Dataflow: A fully managed service for processing streaming and batch data, but it lacks the comprehensive orchestration capabilities of Cloud Composer.
• D. Cloud Dataprep: Focuses on data preparation and cleaning, not on orchestrating data pipelines.