Which statement is true for a BPMN subprocesses?

Which statement is true for a BPMN subprocesses?

A.
It has access to the data variables of the main process.

B.
Data have to be explicitly passed back and forth between the main process and the subprocess.

C.
The subprocess can be reused and called from other processes.

D.
The sequence flow inside a subprocess can be diverted and joined to the main flow without going through
an end event.