The correct answer is C because Snowflake supports external stages from all three major cloud storage providers (Amazon S3, Google Cloud Storage, and Microsoft Azure Blob Storage) regardless of where the Snowflake account itself is hosted. The community discussion shows strong consensus (65% voted C) with multiple users citing official Snowflake documentation that confirms Google Cloud Storage buckets are valid external stage sources even when Snowflake is on Azure. Option D (Windows server file share on Azure) is incorrect because Snowflake only supports Azure Blob Storage, Data Lake Storage Gen2, and General-purpose storage accounts - not Windows file shares. Options A and B (FTP/HTTPS servers) are not supported external stage sources in Snowflake.