What is the ideal method of copying data between two opened files?

A.
copy($source_file, $destination_file);

B.
copy(destination_file, $source_file);

C.
stream_copy_to_stream($source_file, $destination_file);

D.
stream_copy_to_stream($destination_file, $source_file);

E.
stream_bucket_prepend($source_file, $destination_file);