What is the maximum passenger capacity that defines a commercial motor vehicle when transporting for compensation?

The correct answer is based on the definition set by the Federal Motor Carrier Safety Administration (FMCSA) regarding commercial motor vehicles (CMVs) that transport passengers for compensation. A commercial motor vehicle is defined as a vehicle designed or used to transport more than 8 passengers (including the driver) for compensation, or more than 15 passengers (including the driver) when not for compensation.

In this context, the critical threshold for defining a commercial motor vehicle is the number of passengers the vehicle is designed to carry. Since the question pertains specifically to transporting passengers for compensation, the critical number that establishes this condition is indeed 9 passengers: this includes the driver, making a total of 8 passengers in addition to the driver. Any vehicle capable of carrying this number is classified as a commercial motor vehicle under the guidelines.

The other options do not align with this definition because they either fall below or are above the relevant passenger capacities that impact the classification as a commercial vehicle for compensation purposes. Specifically, vehicles designed to carry fewer than 9 passengers would typically not meet the commercial requirements, while those that carry 15 or more respectively fall into a different regulatory category.