Residents of Milatia are known for their longevity. Nutritionists maintain that the Milatians can attribute their increased lifespans to their diets. In addition to consuming a diet full of leafy greens, they also have a low intake of saturated fats, which have been implicated in heart disease and atherosclerosis. Therefore, if one wants to have increased longevity, he or she should follow a Milatia based diet.

Which one of the following is an assumption on which the argument depends?

A. Other aspects of the Milatians’ lifestyle do not affect the observed trend of longevity in Milatia.
B. Adopting another people’s eating habits will, in of itself, not confer the same advantages, unless a person incorporates exercise into his or her life.
C. The Milatian lifespan has a relatively uniform distribution, with very few dying young from natural causes.
D. Milatians are the only people in whom there is a perceived link between diet and longevity.
E. All Milatians are known to have lifespans that are above average.