A. Medium Scale Integrated Circuits
B. Medium System Integrated Circuits
C. Medium Scale Intelligent Circuit
D. Medium System Intelligent Circuit

Solution

A. Medium Scale Integrated Circuits

Explanation

After the invention of IC chips the development of computers plunged into next phase. Small Scale Integration and Medium Scale Integration (SSI and MSI) were used in third generation of computers and Large Scale Integration and Very Large Scale Integration (LSI and VLSI) are being used in fourth generation of computers. People are now expecting ULSI (Ultra Large Scale Integration) Circuits to be used for fifth generation computers.