While Some Believe That Increases in Science and Medical Technology

While some believe that increases in science and medical technology were the reasons for improved general health in the twentieth century,historians and social scientists __________.

A) believe that evolution allowed people to develop stronger immunities to diseases that once caused epidemics
B) argue that the developing middle class made healthcare more available to the population
C) point to improvements in sanitation and hygiene as having a greater influence
D) theorize that changes in habits at work,school,and other institutions had a greater influence than science