The image titled "Study of Clouds with a Sunset near Rome" by Simon Alexandre Clement Denis is primarily portraying clouds and a sunset, suggesting a serene and possibly dramatic sky rather than any stormy weather. Therefore, the most likely response among the options provided is:
clouds gathering before a storm
Even though it may not specifically depict a storm, the presence of clouds in the title indicates an atmospheric scene that is more aligned with this option rather than a clear, sunny day or a snowstorm.