You work as the Enterprise application developer at Domain.com. The Domain.com network consists of a single Active Directory domain named Domain.com. All servers in the domain run Windows Server 2003. The design of applications forms part of your responsibilities at Domain.com. Certkiller .COM operates as an insurance company.
You are currently developing an enterprise application that is destined to allow the Domain.com customer to pay their premiums for the insurance services rendered to them. The Domain.com customers have a choice in payment options: credit card or debit order. In your development of this application you took a decision to model the requirements on a class diagram. You now need to choose the appropriate class diagram.

What should you do? (To answer, click on the correct class diagram.)

A.

B.

C.

D.

Explanation:
The particular diagram models generalization. Taking into account the requirements, a customer may pay his/her premiums via credit card or debit order. This means that the payment class can be specialized though Credit Card and Debit Order classes. In a class diagram that models generalization, the triangle points to the general element.
Incorrect answers:
A: This particular diagram models composition and indicates that a payment of premiums has a credit card and a debit order, which is not the case.
C: This particular diagram models composition and indicates that a credit card and a debit order has a payment, which is not the case.
D: This particular diagram also models generalization, however, it is depicted in the wrong direction. This will indicate that a payment of premiums is both by credit card and debit order, which is not correct. The payment of premiums is either one of the two, but not both.