The most appropriate matching for the following pairs

X: m=malloc(5); m= NULL;
Y: free(n); n->value = 5;
Z: char *p; *p='a';

1: using dangling
2: using uninitialized pointers
3. lost memory
is:

Consider the following C declaration

struct {
      short s[5];
      union {
      float y;
      long z;
      } u;
}t;

Assume that objects of the type short, float and long occupy 2 bytes, 4 bytes and 8 bytes, respectively. The memory requirement for variable t, ignoring alignment considerations, is

The value of j at the end of the execution of the following C program

int incr (int i)
{
     static int count = 0;
     count = count + i;
     return (count);
}
main () {
   int i,j;
   for (i = 0; i <= 4; i++)
   j = incr(i);
}

is

Let $$L$$ denote the language generated by the grammar $$S \to 0S\left. 0 \right|00.$$ Which one of the following is true?