Final answer:
Between 1900 and 1955, the health trend in the United States showed a rise in chronic diseases and an increase in life expectancy, attributed to improvements in public health, medical advancements, and behavioral changes.
Step-by-step explanation:
The correct answer is (a) There was a rise in chronic diseases such as heart disease and cancer. During the period between 1900 and 1955 in the United States, there was an overall decrease in communicable diseases, thanks to improvements in public health, sanitation, behavior change, and medical advancements such as vaccines and antibiotics. As a result of these health improvements and changes in lifestyle, chronic diseases like heart disease and cancer became more prevalent. Lifespans increased as well, reflecting these improvements in health and medicine.
Life expectancy in the United States has been on the rise due to several key factors. Systems for providing clean water and disposing of human waste prevented many diseases, changes in public behavior—including hygiene and reduced smoking—improved health, and significant medical advancements like immunizations and antibiotics greatly reduced many infectious diseases. These innovations have led to an increased life expectancy and a shift in health trends towards more chronic noncommunicable diseases.
Contrary to a rise in communicable diseases, advancements in public health and medicine significantly lowered mortality rates due to infectious diseases while contributing to a rise in noncommunicable diseases. This shift is also influenced by lifestyle changes, where increasing sedentary behavior and changes in diet play a role. It's clear that the crude mortality rate decreased during this time due to better health practices and medical improvements.