The correct answer is B: Using Databricks notebooks' real-time coauthoring feature on a single notebook. This feature allows multiple users to work on the same notebook simultaneously, seeing each other's changes live, which eliminates the need for copying notebooks to personal folders and manually merging changes. This approach enhances collaboration and minimizes the risk of overwriting work.

• A is incorrect because exporting notebooks as HTML is for sharing static views and does not support collaborative editing.
• C is incorrect because while source control is beneficial, local copying and editing are inefficient and prone to conflicts.
• D is incorrect because storing notebooks as dbc files in a data lake does not enable real-time collaboration.
• E is incorrect because automatic change tracking and versioning, while useful for reviewing past versions, do not facilitate simultaneous editing by multiple users.