ASVAB Paragraph Comprehension Practice Test 731157

Question 2 of 5
In linguistics, the comparative method is a technique for studying the development of languages by performing a feature-by-feature comparison of two or more languages with common descent from a shared ancestor, as opposed to the method of internal reconstruction, which analyzes the internal development of a single language over time.
Which of the following would be the most useful for someone using the comparative method in linguistics when studying a particular language?
The same text written in two different dialects of the language.
An ancient text written in the language.
Two editions of the same text written one-hundred years apart.
Old folk songs that have been passed down among generations of speakers of the language.