For the differential amplifier shown below, assume IQ to be a current source with output resistance Rout = 100 kohms. Ignoring mismatches, what is the common-mode gain of the circuit if the output is taken differentially (i. e. , vo = vc1 - vc2)? Assume Rc = 20 kohms. Acm = 0 Acm = 0.008 Acm = 0.02