Explanation:

- Option 1: Copies of that document

Copies are often used to provide evidence when the original document is unavailable. They are considered secondary evidence.

- Option 2: Oral account of the contents of the documents

An oral account involves verbally describing what's in the document, often used when physical or digital copies cannot be accessed.

- Option 3: Both (a) & (b)

This includes both copies and oral accounts as forms of secondary evidence. Secondary evidence involves any proof that is not the original document.

- Option 4: Only (a) & not (b)

This suggests that only copies, and not oral accounts, are considered secondary evidence. It excludes oral accounts which can also be secondary evidence.