Which of the following statements regarding the protection of the cross-connecting plate 1+1 is correct?

The source business board sends services to the main and standby crossover boards. .

After the service cross-connection is completed, the active and standby cross-board sends the data of the primary cross-board to the receiving service board.

The receiving service board can only receive data from the active cross-link board

The bus of the two cross-connected modules works independently and does not interfere with each other. .

Dual bus system structure indicates that the service board performs dual data transfer to the cross-connection side and selectively receives data on the cross-connection side. .

Both cross-connecting plates have the same configuration. The service board will selectively receive services from one of them based on the quality of service and the status of the cross-connecting board. .