All of the following are mentioned in the passage

单项选择题

No other country spends what we do per capita for medical care. The care available is among the Best technically, even if used too lavishly and thus dangerously, but none of the countries that stand above us in health status have such a high proportion of medically disenfranchised persons. Given the evidence that medical care is not that valuable and access to care is nor that had, it seems most unlikely that our bad showing is caused By the significant proportion who are poorly served. Other hypotheses have greater explanatory power: excessive poverty, both actual and relative, and excessive affluence.
Excessive poverty is probably more prevalent in the U. S. than in any of the countries that have a better infant mortality rate and female life expectancy at birth. This is probably true also for all but four or five of the countries with a longer male life expectancy. In the notably poor counties that exceed us in male survival, difficult living conditions are a more accepted way of life and in several of them, a good basic diet, basic medical care and basic education, and lifelong employment opportunities are an everyday fact of life. In the U. S. a motional unemployment level of 10 percent can be 40 percent in the ghetto while less than 4 percent elsewhere. The countries that have surpassed us in health do not have such severe or entrenched problems. Nor are such a high proportion of their people involve in them.
Excessive affluence is not so obvious a cause of ill health, but, at least until recently, few other nations could afford such unhealthful ways of living, excessive intake of animal protein and fats, dangerous intake of alcohol and use of tobacco and drugs (prescribed and proscribed), and dangerous recreational sports and driving habits are all possible only because of affluence. Our heritage, desires, opportunities, and our machismo, combined with the relatively low cost of had foods and speedy vehicles, make us particularly vulnerable to our affluence. And those who are not affluent try harder. Our unacceptable health status, then, will not be improved appreciably by expanded medical resources nor by their redistribution so much as by a general attempt to improve the quality of life for all.

All of the following are mentioned in the passage as factors affecting the health of the population EXCEPT ______.

A．the availability of medical care services
B．the genetic endowment of individuals
C．the nation’s relative position in health status
D．an individual’s own behavior