Final answer:
LTL carriers operate on the premise of consolidating multiple shipments (option c) into a single truckload. This allows for efficient use of cargo space and enables shippers to pay only for the space they require.
Step-by-step explanation:
Less-than-truckload (LTL) carriers operate under the premise of consolidating multiple shipments. This method is designed to maximize efficiency by combining smaller shipments from various customers into a single truckload. This allows each shipper to pay only for the portion of the truck space they use, as opposed to paying for a full truckload when they don't have enough items to fill it.
The alternative options do not accurately describe the primary operating premise of LTL carriers. For instance, LTL carriers do not necessarily operate on the premise of maximum load capacity, as they do not require filling an entire truck to departure. They also are not based on exclusive contracts which would imply dedicated service for specific customers' goods only. And while they do offer point-to-point delivery, it is within the context of servicing multiple customers through their shipping network rather than direct, exclusive routes.