One could argue that germ theory is the major driver of water-related technological innovations of the 20th When microbes could be viewed through Leeuwenhoek's lenses in 1676, and when John Snow demonstrated that clean water stopped the spread of cholera in 1854, clean water became a necessity. In the 21st Century, access to water is considered to be a human right. How this right is enforced within countries requires __ in most parts of the world. This is because it is very difficult to contain naturally occurring and manufactured water systems within political boundaries.
a. State-level appropriation of funds
b. Cooperation between countries
c. National policies
d. Control of headwaters by private companies