Answer:
B. The entity CUSTOMER with the attribute PURCHASE
Step-by-step explanation:
Entities are distinct or non distinguishable real-world objects,an example is a person or customer, product etc.
Attributes are the features or characteristics of an entity, an example is name, sales etc.
A good example to best illustrate the relationship between entities and attributes is an inventory and sales record which store information about products, customers, and sales, the product and customers are entities, while sales is the relationship between customers and products.