Which sentence best supports the central idea that public works are not fully appreciated

1) no population can thrive without good schools and other words that promote the public good

2) this in normas project span thousands of miles and was not fully completed for decades

3) it is unlikely that most people thought about their local sewer system today although they relied on it

4) roads sidewalks and bridges are some of the more obvious examples but public works is a huge category that also includes water resources and electricity