a. Explain in detail how the URL entered by the used is resolved in the IP address and which software is required to setup this service on Linux OS. [4] b. Explain the following about VI: i. What are its different modes of VI? [1] ii. What are the editing commands in VI?[0.5] iii. What are search and replacing commands V1?[1] iv. How VI editor is opened and how files are saved in VI?[0.5) Give your answers with proper description