1. (4 marks) Write a C function to set a bit in the binary representation of an unsigned integer number of four bytes (bits counting from right to left as bit0, bit1, bit2, ..., bit31), and display both the number and the number after bit set in hexadecimal format. The function prototype is as follows, void set_a_bit (unsinged int n, unsigned int s); /* set bit s of number n. */ For example, a call of the function in the program, set_a_bit (260, 3); will output set bit3 in Ox104 is 0x10C. on the screen.