Final answer:
A standard shipper-carrier contract typically remains constant for all shipments, providing a steady framework for service and cost expectations between the shipping party and the carrier.
Step-by-step explanation:
The true statement about a standard shipper-carrier contract is that b) It remains constant for all shipments. These contracts are generally not renegotiated for each individual shipment; rather, they are designed to cover multiple shipments over a period of time as specified within the contract.
This provides a consistent framework of service expectations and cost understanding between the shipper and the carrier.