Puzzle SL8

Examine the following code:

#include <stdio.h>
int main( void )
{
 
  {
    int b = 99;
    printf("b=%d\n", b );
  }
  
  {
    int a;
    printf("a=%d\n", a );
  }

  return 0 ;
}

Question 1: Will the program compile?

Question 2: Is it predictable what this program will write to the monitor?

Question 3: What might the program write to the monitor, mostly as an accident?