The Article Was Headlined, "Two Cups of Coffee Can Reduce

Multiple Choice

The article was headlined, "Two Cups of Coffee Can Reduce the Risk of Liver Disease, Study Finds." A meta-analysis, based on combining nine previous studies involving 430,000 individuals, concluded that consumption of two cups of coffee a day reduced the chance of cirrhosis of the liver by 44 percent; even greater consumption was found to further reduce the risk of the disease.
The explanatory variable in this study is:

A) incidence of cirrhosis of the liver.
B) coffee consumption.
C) There is no explanatory variable because it is a meta-analysis.
D) not given in the quote above.