Option D is the correct answer as it involves implementing Azure Databricks with Azure Data Lake Storage Gen2 (ADLS Gen2) as the default storage account, and enabling hierarchical namespace, access control, and encryption at rest for secure data storage. This approach ensures that the data is secure and protected against unauthorized access and data breaches. Option A is partially correct but does not address the use of ADLS Gen2 and its features. Option B is incorrect as it does not address the specific security measures for Azure Databricks and ADLS. Option C is incorrect as it does not provide a comprehensive solution for data security in the data analytics environment using Azure Databricks and ADLS.