The medical advancements came out of research occurring during WWI. The polio vaccination introduced in 1955, changed the outlook for children in America who may have been diagnosed with the disease. This innovation extended the life expectancy and made it more likely children would make it to adulthood. This increased the size of families as more children would live past childhood and not die from now preventable diseases.
The Green Revolution will emerge in the 1960s after the release of Rachel Carson's book Silent Spring. This book showed the damaging impact people had on the environment. Efforts would produce a return to more natural methods as well as recycling programs. In the 1970's, Nixon introduced Earth Day and created the EPA.
The space program was created as an extension to the arms race with the USSR. Rocket technology helped to create the NASA program which was a federal means of producing innovation for both war and space travel. This drive became an important part of the Cold War and the ability to show the USSR that the US was more advanced and more intelligent.
The population decreased.<span />
The answer is A because they needed their land
