The most effective reason to refute the counterclaim would be: "It is true that Bob Dylan has published traditional poetry and prose. However, one book of poetry and one memoir would not qualify him for the prize. The prize was awarded based on his songwriting, which does not qualify as literature."
This response directly addresses the core argument of the counterclaim by emphasizing that the Nobel Prize in Literature was specifically awarded for his songwriting, not necessarily for his other written works. By focusing on the criteria for the award and asserting that his songwriting is distinct from traditional literature, it effectively weakens the counterclaim's argument about his prose and poetry contributions.