Explanation:

Multiprogramming, which allows multiple programs to reside in memory simultaneously and share the CPU, became a prominent feature in the Third Generation of computers. This generation, characterized by the use of Integrated Circuits (ICs), saw the development of sophisticated operating systems that could manage these complex tasks, along with time-sharing and remote processing. The (a) First generation used vacuum tubes and typically ran one program at a time. The (b) Second generation introduced transistors and batch processing but multiprogramming was not yet widespread. The (d) Fourth generation further advanced with microprocessors and personal computing. Therefore, multiprogramming significantly emerged in the Third generation ($ \text{c} $).