The answer is D. They are realistic and show the American West. The reason is because, well, that is what Albert Bierstadt painted. Albert was from Germany, but he made several journeys to the west and made paintings of what he saw.
If untreated HIV advances to AIDS, the body becomes prone to opportunistic infections. AIDS increases a person's risk for many infections, including a herpes virus called cytomegalovirus. It can cause problems with the eyes, lungs, and digestive tract.
The answer is: Robert Henri.