The structure of "Mending Wall" significantly contributes to its themes and the nature of the conversation between the speaker and his neighbor.
The correct interpretation would be "The poem is in multiple unrhymed stanzas to show that the conversation between the speaker and his neighbor is fragmented." Unrhymed stanzas reflect the fractured and often tense nature of their dialogue, illustrating differing perspectives on boundaries and relationships. The lack of a rigid rhyme scheme can enhance the sense of spontaneity and reflection in their conversations, allowing the speaker's voice to flow freely as he contemplates the meaning of walls and barriers. This structure emphasizes the ongoing, unresolved nature of their discussion about personal and social boundaries.