When people mistake changes in nominal prices for changes in real prices, what has occurred?

How were Smith, Ricardo, Malthus and Marx, in their own ways, pessimistic about long-term development?

What will be an ideal response?

The transcontinental railroads were completed in the 25 years

A. before the Civil War. B. after the Civil War. C. after 1890. D. after the 20th century began.