Which operation should be used to update a single document in MongoDB?

The operation to update a single document in MongoDB is updateOne(). This method is designed specifically for this purpose, allowing you to specify a filter to choose which document to update, along with the update operations that should be applied.

When using updateOne(), you typically provide two parameters: a filter to select the document and an update object to define the changes to be made. This ensures that only one document that matches the filter criteria will be updated, making it ideal for scenarios where you know there is only one specific document to change.

The other options do not correspond to any existing methods in MongoDB's API for updating documents. This reinforces the importance of using the correct method name to ensure that operations are executed successfully in your code and meet the intended functionality.