B, the Incas- google Machu Picchu and you'll see precisely fitted blocks of stones in their buildings and structures
The overall trend of spending during presidential campaigns since the 1960´s has shown an enormous increase. The explanation resides in various factors: - inflation (change of the value of the dollar, making necessary more dollars to achieve the same); -also the equation that there are more inhabitants, meaning, more donors. - Since the income of the people increased, there is also more money to donate.
Answer:
D. OPEC actions
Explanation:
The downfall of the US oil industry in the 1980s was caused by a reduced demand for oil caused by the energy crises of the 70s and with this reduced demand, there became an oil glut, because the production was also increased.
Therefore, this downfall of the oil industry in America in the 1980s was caused by increase in oil prices by OPEC (Organisation of Petroleum Exporting Countries).