Which of the following is a wrong understanding of the database cluster model?

Which of the following is a wrong understanding of the database cluster model?
A . The two key points of a database cluster are: ① having two or more database server clusters, and ② being able to provide transparent services.
B . Synchronize the database. After the database client issues a data update request, the node that receives the request will copy and transmit the updated data to other nodes in the cluster while returning the result to the client.
C . Database clusters include two models: synchronous clusters and asynchronous clusters
D . Asynchronous database: After the database client issues a data update request, the node that receives the request immediately returns the result to the client, and the updated data will be copied and transmitted to other nodes in the cluster at a certain time.

Answer: B