Which of the following inclusions represents a remnant of nuclear DNA in an RBC?

Howell-Jolly bodies are indeed the correct choice for representing remnants of nuclear DNA in a red blood cell (RBC). These inclusions are typically small, round structures visible in stained peripheral blood smears. They originate from the nucleus of developing red blood cells and are remnants of DNA that have not been extruded during the maturation process.

In normal circumstances, the spleen removes these bodies, so their presence is often associated with cases of splenic dysfunction or absence of the spleen (asplenia). The detection of Howell-Jolly bodies can, therefore, indicate certain morphologic abnormalities in red blood cell development or suggest issues with splenic function.

The other options represent different types of inclusions found in red blood cells that do not pertain specifically to remnants of nuclear DNA. For example, Cabot rings are associated with abnormal cell division and are made up of ring structures, while Pappenheimer bodies consist primarily of iron and basophilic stippling reflects disturbances in hemoglobin synthesis, often linked to lead poisoning or other anemias. Each of these inclusions has its clinical significance, but Howell-Jolly bodies directly relate to remnant nuclear DNA, making it the correct answer.