Which of the following reasons may cause a business error? (Multiple choice)
A . The tail wire connector is seriously polluted
B . Dispersion compensation is unreasonable, such as under- or over-compensation
C . The temperature in the equipment room is too high
D . Transmitting laser performance degradation of the originating OTU board
E . The optical power of the incoming fiber is too high or too low
Answer: ABCDE