Which of the Following BEST Explains the Concept of RTOs

Which of the following BEST explains the concept of RTOs for restoring servers to operational use?

A) To reduce the amount of data loss that can occur in the event of a server failure
B) To ensure the restored server is available and operational within a given window of time
C) To ensure the data on the restored server is current within a given window of time
D) To reduce the amount of time a particular server is unavailable and offline