Which of the following choices meets the minimum requirement needed to create specialized waveforms that are used in digital control and sequencing circuits?
A.basic gates, a clock oscillator, and a repetitive waveform generator
B.basic gates, a clock oscillator, and a Johnson shift counter
C.basic gates, a clock oscillator, and a DeMorgan pulse generator
D.basic gates, a clock oscillator, a repetitive waveform generator, and a Johnson shift counter