The correct answer is to use bq query --dry_run to estimate the bytes read by the query, then use this figure in the Pricing Calculator for an annual cost estimate. This method aligns with Google Cloud's best practices for pricing queries, which bill based on bytes read. Options A and D are incorrect because they suggest using gcloud commands, which are not suited for BigQuery operations. Option B is incorrect as it misapplies the gcloud query --dry_run command, which is not the recommended tool for BigQuery cost estimation.