Unlike an op amp, a comparator IC usually has Select one of ... A) an open collector B) a high impedance C) inverting output stage. In this case there must be a Select one of ... A) shunt B) low-value C) variable D) pull-up resistor connecting the Select one of ... A) inverting input B) output C) non-inverting input D) negative supply line to the Select one of ... A) inverting input. B) non-inverting input. C) positive supply line. D) output.