What is the basic unit of framing in SDH and the bit rate for its transmission?
A . STM-1 with a bit rate of 1.544 Mbit/s
B . STM-1 with a bit rate of 2.048 Mbit/s
C . STM-1 with a bit rate of 51.84 Mbit/s
D . STM-1 with a bit rate of 155.52 Mbit/s
Answer: D