Imagine that a historian has discovered a diary written in 1848 by another German revolutionary. Which statement best explains how this discovery could be used?

The correct answer to this open question is the following.

You forgot to include the options for this question. However, we can say the following.

The statement that best explains how this discovery could be used is "It could be used to corroborate Schutz's recollection of the revolution"

This document would be very important in that it could represent another valid version of how things happened during the German Revolution. It could help historians to prove some things, compare others, corroborate dates and facts, or in its case, correct some others. This piece of information would add value to what we already know.