Final answer:
Middle-aged businessmen are considered at low risk for iron-deficiency anemia due to their generally sufficient iron intake and absence of menstruation, which is a common cause of anemia in women.
Step-by-step explanation:
The population group considered at low risk for iron-deficiency anemia is D) middle-aged businessmen. This group typically is not subject to the same risk factors as groups like pregnant women, infants, and preschool children who have higher iron needs, or vegetarians and vegans who might not get enough dietary iron if not consuming iron-rich plant-based foods or supplements.
Statistically, around 20% of women of childbearing age in the United States suffer from iron-deficiency anemia, much due to menstrual blood loss, while only about 2% of adult men are affected. As middle-aged men do not menstruate and generally have a diet that includes iron from meat and other sources, they are considered at a lower risk.
It's important to involve a variety of iron-rich foods in one's diet, such as red meat, legumes, and spinach, to help prevent anemia. Additionally, it is crucial to understand that certain health conditions and lifestyle choices, such as excessive alcohol consumption and avoiding specific food groups, can increase the risk of anemia.