What is defined as a common carrier?

A common carrier is defined as a transportation service that is available to the public for the carriage of goods or passengers. This definition emphasizes that such carriers are legally obligated to provide their services to anyone who requests them, provided that the customer pays the necessary fare or fee. This regulatory aspect ensures that the service is impartial and non-discriminatory, making it accessible to all individuals or entities willing to pay.

The other options describe services that either cater to specific clientele or operate under special conditions, thus falling outside the definition of a common carrier. For example, a private transport company for passengers, like a bus service that does not serve the general public under an obligation, or specialized services tailored for specific clients, do not meet the criteria of a common carrier. The exclusive transport service also does not reflect the open access characteristic that defines common carriers. Therefore, the correct choice highlights the legal obligation and public availability that distinguishes common carriers in the transportation industry.