Explanation
The evolution of Operating Systems across different computer generations is classified as follows:
A. First Generation (1945–1955) → 4: Relied on Vacuum Tubes and Plugboards. Programs were executed directly on the machine without an operating system.
B. Second Generation (1955–1965) → 1: Introduced Transistors and Batch Systems. Jobs were collected in batches and processed sequentially to reduce setup time.
C. Third Generation (1965–1980) → 2: Utilized Integrated Circuits (ICs), leading to the development of Multiprogramming and time-sharing operating systems.
D. Fourth Generation (1980–Present) → 3: Powered by Microprocessors (LSI/VLSI), bringing about the era of Personal Computing and user-friendly operating systems.
Therefore, the correct mapping sequence is A-4, B-1, C-2, D-3.
