Final answer:
The percentage of people who are obese have increased most significantly from 1960-2008.
Step-by-step explanation:
The true statement about the weight status trend of US adults aged 20-74 years from 1960-2008 is:
C. The percentage of people who are obese have increased most significantly.
According to the information provided, the rate of obesity has been steadily rising since the 1980s. By 2010, nearly 36 percent of adults over 20 years old were obese and an additional 33 percent were overweight. This indicates that the percentage of people who are obese has increased most significantly over the specified time period.