You are an experienced network administrator in an international corporation. One of your clients asks you to configure a network for a financial trading center which requires multiple high-value transactions. And the transactions are very important to the client. In such a situation, which two of the following are basic and most important requirements concerning the configuration? （）(Choose two.)
- A no single point of failure
- B determine which protocol to use
- C trading database server location
- D deterministic response to all failure