Which of the Following Statements Is True

Which of the following statements is true?

A) "Contract first" design is important to SOA because it makes you think about service contract design options at the same time that you are building the underlying service logic.
B) "Contract first" design is important to SOA because it forces you to establish standardized service contracts prior to the development of the underlying service logic.
C) "Contract first" design is important to SOA because without a contract, services cannot be invoked. However, there is no preference as to when, during the service delivery lifecycle, the contract should be designed or established.
D) "Contract first" design is an unproven design technique that is not commonly employed when delivering service-oriented solutions and is therefore not considered important to SOA.