Giffen goods are those goods

For which demand increases as price increases
That have a high income elasticity of demand
That are in short supply
None of the above

The correct answer is: A. For which demand increases as price increases.

A Giffen good is a good for which the demand increases as the price increases. This is because the good is a necessity for the consumer and they are willing to pay more for it as their income decreases.

Option B is incorrect because a good with a high income elasticity of demand is a good whose demand changes significantly in response to changes in income.

Option C is incorrect because a good that is in short supply is a good that is not available in enough quantity to meet the demand for it.

Option D is incorrect because Giffen goods are a type of good, not a description of a good.