Which is an example of a good with an elastic supply?

Data on exports and imports for the United States over the period from 1890 to 2008 show that

A) the United States had large trade deficits throughout this entire period. B) the United States had large trade surpluses throughout this entire period. C) the percentage of total output exported by U.S. firms fell dramatically during World War I and World War II. D) a higher percentage of U.S. goods was exported in recent years than in earlier years.

The allocation of tax burden

A. is the total tax burden less the excess burden. B. is tax payments plus the excess burden. C. is tax shifting. D. is the tax incidence.