Final answer:
The correct option is a) vocation. Truck transmissions are specifically selected to match the vocation of the vehicle. Vocation refers to the specific job or industry that the truck is intended to be used for.
Step-by-step explanation:
Truck transmissions are specifically selected to match the vocation of the vehicle. The term 'vocation' refers to the specific job or industry that the truck is intended to be used for. Different vocations require different performance characteristics from the transmission, such as torque, power, and gear ratios. For example, a truck used for heavy-duty hauling may have a transmission that is geared for a high-torque output, while a truck used for long-distance transport may have a transmission that is geared for fuel efficiency.
Size, synchronization, and action are unrelated to the selection of truck transmissions. Size generally refers to the physical dimensions of the vehicle, synchronization typically relates to the coordination of gears in a manual transmission, and action is a vague term that does not have direct relevance to transmission selection.