What changes contributed to the massive population growth in europe from 1800–1900? select all that apply. (3 choices! ) a. reductions in the average age of marriage increased the number of children born to each woman. b. better child-care assistance encouraged middle-class women to have more children. c. improved food production, storage, and distribution contributed to better nutrition and improved health. d. improvements in public sanitation reduced death rates. e. rising incomes resulted in higher birth rates for both low-income and middle-class women. f. advances in medical practices and procedures led to lower death rates of those receiving medical care.