• (A) they should be left disconnected so as not to produce a load on any of the other circuits and to minimize power loading on the voltage source.
• (B) all unused gates should be connected together and tied to v through a 1 k resistor.
• (C) all unused inputs should be connected to an unused output; this will ensure compatible loading on both the unused inputs and unused outputs.
• (D) unused and and nand inputs should be tied to vcc through a 1 k resistor; unused or and nor inputs should be grounded.