The correct response in this context is: The positive connotation contributes to the author’s point of view that we should embrace the abundant responses to art.
The word "fertile" generally has a positive connotation, suggesting abundance, creativity, and richness. By using this connotation, the author likely emphasizes that a wide range of responses to art—regardless of whether they are critical or not—can foster a deeper discussion and engagement with the artwork and its themes, such as those represented by Maggi Hambling's sculpture of Mary Wollstonecraft.