What is a key characteristic of common carriers in relation to service provision?

Common carriers are defined by a fundamental principle of non-discrimination in their operations. This means they are legally obligated to provide services to all individuals or businesses without unfairly excluding certain customers or favoring others. The essence of a common carrier's role is to serve the public interest, ensuring equal access to transportation or delivery services regardless of the customer's identity or the nature of the goods being transported.

The nature of their business hinges on this non-discriminatory practice, as it fosters fair competition and allows for broader access to essential services that drive commerce and trade. Consequently, this characteristic differentiates common carriers from private carriers, who may choose their clientele and selectively refuse service based on their own criteria.

In contrast, other options highlight characteristics that do not typically align with the legal and operational framework that governs common carriers.