Final answer:
The author of the paragraph reinforces the main idea that the Grimm brothers' narratives depict brutal living conditions by discussing their intent to preserve German culture through folklore, which often included harsh realities, and by mentioning their comprehensive work on a German dictionary.
Step-by-step explanation:
The author supports the main idea in the paragraph about the Grimm brothers predominantly with option A) a claim that the narratives show brutal living conditions. This is evident when discussing how the Grimm brothers collected folk tales to grasp the 'essence' of what it meant to be 'German', reflecting on the nation's spirit and core identity through stories. The Grimms' work is regarded as an effort to preserve the purity of German cultural elements and their fairy tales which often contained elements illustrating the harsh realities of life.
Furthermore, evidence demonstrating the topic sentence's point is also provided by outlining their philological work and dedication to capturing a comprehensive German Dictionary. This level of detail reinforces the claim regarding their intent to preserve the German language and identity, which is reflected through the tales, some depicting brutal living conditions.