The Pimas Are a Group of People Living in the South-Western

The Pimas are a group of people living in the south-western United States and Mexico. Although Pima Indians living in the United States and Mexico have a similar genetic background, a five-fold increase in the incidence of type II diabetes mellitus among US Pima has been reported. The body mass index of Mexicans of non-Pima descent, Mexicans of Pima descent, and Pimas living in the US is shown in the figure. Based on this information and the graph, what can you infer about the incidence of type II diabetes mellitus?

A) Obesity is a risk factor for development of type II diabetes mellitus.
B) If you maintain a normal body weight (body mass index less than 25) , you will not get type II diabetes mellitus.
C) The incidence of type II diabetes mellitus has increased in the past 10 years.
D) People who develop type II diabetes mellitus are typically diagnosed in childhood or adolescence.