A) The TM1 optical port must be connected to the TMI1 optical port. and B) The TMB1AST2 board supports the IEEE 1588v2 clock processing and OTDR functions. and C) When the board is working with a DFIU03/DFIU04 board, the OSC optical port must be configured with an optical module that supports the 1511 nm wavelength. and D) When the board is working with a DSFIU01/DSFIU02 board, the TM1/RM1 optical port must be configured with an optical module that supports the 1511 nm wavelength, and the TM2/RM2 optical port must be configured with an optical module that supports the 1491 nm wavelength.