What does SAP recommend when importing transport requests? (There are 3 correct answers to this question)

What does SAP recommend when importing transport requests? (There are 3 correct answers to this question)
A . Transport requests should only be imported if the software component vector of the transport requests fit to the software components and their Support Package level of the target system.
B . Transport requests should be imported into the productive system one by one in the order of their sequence in the import queue
C . Transport requests should always be imported into the productive system in the sequence of their export from the development system
D . In general importing transport requests into the productive systems requires a maintenance window (downtime window).
E . Transport requests should be imported project wise into the productive system

Answer: A,D,E