The main aim of which of the following is to make a network work as a single…

The correct answer is Option A, which states that only distributed computing aims to make a network work as a single computer. Distributed computing is designed specifically to integrate multiple independent computers into a unified system that appears as one entity to the user. This allows for resource sharing, fault tolerance, and seamless operation across a network. In contrast, parallel computing focuses on executing multiple calculations simultaneously to solve a single problem faster. While it involves multiple processors, its primary goal is performance acceleration rather than presenting the system as a single computer to users. Therefore, parallel computing does not fit the specific definition provided in the question.