9-19B2 D
 What type of code is used for DSC transmissions? 
A. A 7 bit code with a constant ratio of 4/3 between the 1s and 0s.
B. A 7 bit code followed by an error check character at the end.
C. A 10 bit code followed by an error check character at the end.
D. A 10 bit code with 7 bits used for information and 3 bits used for error correction.
