Final answer:
The narrowing gap in life expectancies between black and white Americans is partially due to lifestyle factors leading to lower life expectancy among white, rural Americans. These include opioid addiction, limited healthcare access, and economic stresses. The overall decrease in mortality rates from major diseases also contributes to this trend.
Step-by-step explanation:
The gap between life expectancies of black and white Americans has been closing, primarily due to a combination of factors affecting health outcomes. Among the given options, C. Lifestyle factors have lowered life expectancy more for white, rural Americans is a reason contributing to the closing gap. This includes a variety of contributors from socioeconomic to healthcare availability, which can disproportionately affect different populations.
While the overall mortality rate has dropped for all races due to declining deaths from cancer, heart attacks, and strokes, lifestyle factors in certain geographical areas have had a distinct impact. For instance, white, rural Americans have been facing their own set of challenges that include higher occurrences of opioid addiction, as well as limited access to healthcare services, which can lead to a higher mortality rate.
These factors, combined with chronic diseases and economic stresses, have contributed to lowering life expectancy in these regions more than for urban populations, thus narrowing the gap between black and white life expectancies.