What defines exempt carriers?

Exempt carriers are defined as entities that transport specific commodities under certain regulatory exemptions. This classification allows them to operate without being subject to the same extensive regulations that typical for-hire carriers face, particularly in regards to pricing and service offerings. The focus on certain commodities and specified geographical areas distinguishes exempt carriers from standard carriers who must adhere to broader regulatory requirements.

The other choices do not accurately capture the essence of what defines exempt carriers. Availability to the public with special treatment is more reflective of different regulatory classifications rather than the specific nature of exempt carrier operations. Operating solely within a single city pertains to a geographic limitation rather than the types of goods transported, and higher rates due to limited availability doesn't align with the regulatory framework which typically allows exempt carriers to operate based on different criteria rather than pricing structures influenced by availability.