Dirt Is Not Dirt When It Comes to Baseball Fields

Dirt is not dirt when it comes to baseball fields.About two-thirds of the pro baseball fields get 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.Roger Bossard,the Blue Jays 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.An increase in the price of Partac Peat will not affect the demand for the product because many groundskeepers believe there is no substitute for the product.Thus,what is demand for Partac Peat?

A) elastic
B) heterogeneous
C) intangible
D) inelastic