They thought that it might keep them safe from harm.
Answer:
Disadvantages of water transfer schemes:
The dams and aqueducts (bridges used to transport water) that are needed are expensive to build;
Building dams can have a negative environmental impact, this includes large-scale flooding of natural habitats;
Fish migration can be disrupted by dams;
24.13million is the population of Australia
The correct answer is - C.) eliminating barriers to trade benefits the economies of member nations.
The regional trade blocs, in fact all trade blocks, are very useful for the economies of the countries that are members in the trade block. The benefit can be seen in the economic sector, as the countries can both, export products on larger markets without tariffs, and import products without imposing tariffs, which benefits the consumers as the prices are lower in that way.
The trade blocks have become a common thing in the world during the 20th century, and that has helped the economies of lot of countries, as well as the choices available and buying power of the consumers.