多项选择题

A. fiber failure between Sites A and D
B. EDFA failure at Site A (clockwise direction)
C. EDFA failure at Site C (clockwise direction)
D. 15216 multiplexer at Site A (counter-clockwise direction)
E. OADM pass-through (West "OUT") failure at site D (clockwise)
F. wavelengths 1 and 3 transmitter failures at Site A (clockwise direction)