write a code which is related to WEB API in C Sharp

Write a ‘Hello World’ program. a. The program has 1 current business requirement – write “Hello World” to the console/screen. b. The program should have an API that is separated from the program logic to eventually support mobile applications, web applications, or console applications, or windows services. c. The program should support future enhancements for writing to a database, console application, etc. i. Use common design patterns (inheritance, e.g.) to account for these future concerns. ii. Use configuration files or another industry-standard mechanism for determining where to write the information to. Write unit tests to support the API. Thank you,