Final answer:
A business rule in a decision table related to shipping rules is best represented by what to charge the customer for shipping based on location, as it pertains to conditional cost logic.
Step-by-step explanation:
The question specifically pertains to a business rule in a decision table relating to shipping rules. Among the given options, the one that best represents a business rule for a decision table in this context is D. What to charge the customer for shipping based on location. This is because a business rule is a statement that defines or constrains some aspect of the business and decision tables often contain conditional logic for costs which are applied to different scenarios, such as geographic locations affecting shipping charges.