Answer 1

Delay function in C. Delay in C: delay function is used to suspend execution of a program for a particular time. Declaration: void delay(unsigned int); Here unsigned int is the number of milliseconds (remember 1 second = 1000 milliseconds).
https://www.programmingsimplified.com/c/dos.h/delay
https://www.geeksforgeeks.org/time-delay-c/
https://stackoverflow.com/questions/27447195/how-to-use-delay-function-in-c-using-codeblocks-13-12mingw