Which of the following function is more appropriate for reading in a multi-word

Which of the following function is more appropriate for reading in a multi-word string?

2) What is the output of this C code?

#include <stdio.h>
     #include <string.h>
     int main()
     {
         char *str = "hello, world";
         char str1[9];
         strncpy(str1, str, 9);
         printf("%s %d", str1, strlen(str1));
     }

3) Which of the following function is more appropriate for reading in a multi-word string?

4) What will be the output of the program ?

 #include<stdio.h>
 int main()
 {
     printf(2+"C Programming MCQ on Study 2 Online\n");
     return 0;
 }

5) What will be the output of the program ?

 #include<stdio.h>
 int main()
 {
     int i;
     char a[] = "\0";
     if(printf("%s", a))
         printf("empty string\n");
     else
         printf("not empty string \n");
     return 0;
 }