What are the authentication options for retrieving documents?

The correct answer highlights the availability of various methods for retrieving documents, including the option to download documents and data in bulk. This means that users can efficiently access multiple files at once, which is particularly useful for those who need to manage large volumes of documents. This option streamlines processes and saves time, making it an essential feature for users who frequently work with extensive documentation.

In contrast, focusing solely on password protection would limit the options for accessing documents, and relying on physical signatures does not pertain to digital document retrieval in an electronic signing context. Moreover, limiting access to one-time use links would not facilitate bulk retrieval, as that implies a more restrictive and less efficient means of accessing documents. Thus, the ability to download documents and data in bulk provides comprehensive access suited for modern document management needs.