C/C++ puzzler #1 - Where do you want to go today ?

First puzzler is in C/C++ and it is based on puzzler found in book Java Puzzlers by Neal Gafter and Joshua Bloch.
Problem:
We have following C program:

/* compile with: cc -g -o test_xxx test_xxx.c */
#include <stdio.h>
#include <stdlib.h>

int main (void)
{
printf("firefox.exe");
http://www.google.com;
printf(":new\n");
exit(0);
}

Options:
What will the program do:
a) print firefox.exe
b) run firefox.exe open http://www.google.com in new tab
c) fail to compile
d) other


Solution: (highlight to see)

First look at source, and you probably think that this couldn't compile. In fact it does. Real puzzler is, why does it compile. Problem seems to be in line http://www.google.com; But let's take a closer look. Is it problem ? It compile because of long forgotten feature of C, which is labels. (Except for kernel source, you'll find plenty of labels there ;) What compiler see is label http: followed by comment //www.google.com;