System documentation that includes the outcome of such structured diagramming techniques as data-flow and entity-relationship diagrams best defines: A. user documentation. B. application documentation. C. external documentation. D. internal documentation. E. embedded documentation.

C. external documentation.

Explanation:

External documentation:

External documents such as vouchers, invoices for payment, tax VAT reports returns are produced because they are needed by someone from outside the company. Within the company, internal documents are used to make decisions about different things.

Internal documentation as comments is written in a program. External documentation would include items such as flow charts, UML diagrams, documentation requirements, development reports, etc.

Therefore the answer is -

C