Researchers Examined 148 Million Tweets in the United States and Discovered

Researchers examined 148 million tweets in the United States and discovered that the best predictor of a county's heart disease death rate was __________________________.

A) a collection of words (in the tweets) associated with economic concerns
B) a collection of words (in the tweets) associated with hostility and aggression
C) a collection of words (in the tweets) associated with being the target of prejudice
D) none of the above