Answer: SELECT

The `SELECT` keyword is used to specify the columns you wish to query, thereby reducing the number of columns processed by BigQuery. Other clauses like `LIMIT`, `BETWEEN`, and `WHERE` do not have this effect. For more details, refer to the [BigQuery launch checklist](https://cloud.google.com/bigquery/launch-checklist#architecture_design_and_development_checklist).

Author: LeetQuiz Editorial Team