The dispersion of a non-zero dispersion shifted fiber is 6 ps/nm*km at 1550 nm and 10 ps/nm*km at 1610 nm. What is the minimum dispersion compensation required if an L-Band DWDM signal travels through 200 km of fiber and has a dispersion tolerance of 1800 ps/nm？（）
- A none
- B -600 ps/nm
- C -200 ps/nm
- D +200 ps/nm
- E +600 ps/nm