Final answer:
A "sale" and "sale items" modeled with a whole-part relationship where the part cannot exist without the whole is known as a composition relationship. Tying sales represent this concept in the business world, where products are sold together mandatorily, often restricting consumer choice, unlike more favorable bundling strategies.
Step-by-step explanation:
If we modeled a "sale" and the "sale items" with a whole-part relationship, it would best be described as a composition relationship. In composition, the part cannot exist independently of the whole, which aligns with the notion that a sale item can't exist apart from the sale itself. Imagining this in a real-world context, tying sales is a situation where a customer can only buy a product if they also buy another product. While tying sales ensure that certain products are sold together, they can be controversial because they may force consumers to purchase items they do not want or need.
For instance, a popular DVD being sold only when the customer also agrees to buy a specific model of a portable TV is an example of tying sales. The portable TV, in this scenario, symbolizes a sale item that does not independently exist without the DVD, the initiating sale. Consumers lose the ability to choose from a range of models, which can be problematic. This is in contrast to bundling, where products or services are sold together, often at a discount, giving consumers extra value while maintaining their freedom of choice.