During a research study it becomes apparent that the procedures being used are causing differential dropout rates. This creates the possibility of confounding due to

Which of the following explains the increased population density in Medieval Europe that led to modern state formation?

A. increase in military expenditures B. increase in tax revenues C. increase in contagious diseases D. increase in food production E. increase in extraction of resources from overseas empires

Compared to the 1940s, the population of Texas is now __________.

A. more urbanized B. much smaller C. more concentrated in rural areas D. less diverse