Final answer:
The persuasive aspect of alliteration in the passage from Ross emphasizes the pervasive, unnoticed grief in Scotland through the echoing 's' and 'sh' sounds.
Step-by-step explanation:
The persuasive use of alliteration in the line mentioned by Ross is found in its sound pattern which is artfully crafted to enhance the meaning of the text. The particular line exemplifies how the repetitive sounds mirror the unending and unnoticed sorrow within Scotland, making the audience feel the weight and ubiquity of grief that has become, as described, a 'modern ecstasy'. The sounds of 's' and 'sh' in 'sighs,' 'shrieks,' and 'seems' are woven together to produce a hissing, almost ethereal echo that underscores the oppressive atmosphere. However, none of the provided options accurately match the effect of the alliteration in this passage. It is not about adaptability, crying out of frustration and anger, or conditions reforming, but about the pervasiveness of sorrow that goes unnoticed.