Dirt is not dirt when it comes to baseball fields.About two-thirds of the pro baseball fields got their dirt from a dirt farm in New Jersey called Partac Peat.The company markets a secret mix for the infield (resilient),the warning track (extra crunchy),and the pitcher's mounds (firm).Mounds come in red,brown,orange,and gray colours.Roger Bossard,the White Sox head groundskeeper,scouted nationwide for dirt before settling on the mix provided by Partac Peat.(He uses sand under the grassy areas of the playing field. )
-Refer to Baseball Dirt.Some of the dirt sold by Partac Peat goes to make clay tennis court surfaces.As the number of people playing tennis increases,so does the demand for new clay courts and,therefore,the demand for Partac Peat clay.This occurs because the demand for Partac Peat is which of the following?
A) inelastic
B) intangible
C) heterogeneous
D) derived

Derived demand refers to a situation where the demand for a good or service is as a result of the demand in another good or service. For example, if the demand for mobile phones increases, the demand for lithium batteries will increase as well.

In the example, Partac Peat clay demand increases as a result of an increase in the demand for tennis playing therefore it is a derived demand based on the demand for the tennis.