J.M.W. Turner paid careful attention to:
a) the small details observed in the English countryside.
b) the interaction of humans in nature.
c) visualizing invisible elements of nature.
d) the interests of the Academy.
As with all multiple choice questions, if you have a course text or lecture notes that have been guiding your instruction, I think that you would be well set to refer to these in answering a question that is driven by a right answer as this one is. Nevertheless, it is a challenging question. One approach that can be taken is to eliminate the bad choices. I am not sure Turner's primary interests would be those of the Academy. His eccentricity and foray into the natural world along with the willingness to sacrifice for his art would be inconsistent with this. As Turner hiked throughout the country side, his work displays a grand scope and possesses so much breadth and depth to it that small details do not seem to be represented in his work. The scope of his work seems to be larger than "small details observed," tossing out the first option.
I think that the second answer is one that I seem to like the best. I am attracted to the visualizing invisible elements in nature. Yet, I think that Turner did see elements in nature and sought to recreate nature's power. When his last words are "The sun is God" and there is such an emphasis on the elements of nature in his work, I don't see them as invisible notions. I think that the invisible element in Turner's work is his imagination, and not the natural setting. That is real and that is represented in his work. I think that Turner paid careful attention to the interaction of humans in nature. Turner believed in both the power of the individual, which would be consistent with his Romanticist notions of the good, and the power of nature, also a part of the Romantic movement. In Turner's work, one finds, a "richness of his exploration of man’s relationship with the environment" that "is beyond measure." It is in this light that I would select the second option as the best answer.