Differential pulse code modulation (DPCM) is a procedure of converting an analog into a digital signal.
Basic concept of DPCM - coding a difference, is based on the fact that most source signals show significant correlation between successive samples so encoding uses redundancy in sample values which implies lower bit rate.
DPCM is form of predictive coding
Answer: D) DPCM
Reference: http://einstein.informatik.uni-oldenburg.de/rechnernetze/dpcm.htm
