DIGITAL circuitry.The output of this is a compliment of the input.This can be built from the transistors like BJT, MOSFET, etc…The structure with the BJT is:The CMOS inverter CONSISTS of the NMOS and the PMOS field-effect transistors connected in one below the other.NMOS inverterPMOS TRANSISTOR Conclusion:From the GIVEN circuits (i), (iii), and (iv) are correct.