How has the MDS 9000 been engineered to promote the use of DWDM for SAN extension?

How has the MDS 9000 been engineered to promote the use of DWDM for SAN extension?

A.
The MDS 9000 has eliminated “Fibre Channel Droop” through proxy acknowledgements of frame arrivals.

B.
The MDS 9000 has implemented buffer to buffer credits per port on the 16 port line card to allow for long distances.

C.
The effects of Fibre Channel Droop are exaggerated and by using light amplification can be nullified.

D.
DWDM has increased available lamdas in order to simultaneously send data on a second lamda, thereby eliminating fibre channel droop.