Cloud Storage objects is the correct option for where raw unprocessed data is typically stored in a lakehouse pattern.

Cloud Storage objects provide durable, scalable, and low cost object storage for raw files such as logs, CSV, JSON, Avro, or Parquet and they serve as the landing zone before pipelines clean or transform the data. This storage integrates with services like Dataflow, Dataproc, and Dataplex which read the raw objects to perform ingestion, cleansing, and format conversions. Keeping raw data in object storage preserves the original data and supports lifecycle rules and partitioning for downstream ETL and analytics.

BigQuery tables are not the usual place to land raw unprocessed files. BigQuery is a managed analytical data warehouse that is optimized for fast queries and for storing processed or modeled datasets rather than acting as a file landing zone. Engineers typically load cleaned or transformed data into BigQuery for analysis.

Cloud Pub/Sub messages are a messaging system for streaming ingestion and decoupling producers from consumers. Pub/Sub is used to transmit events or records in motion and it is not intended to be a durable file store for raw datasets. Persistent raw storage is normally handled by object storage.

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