What is the output of the following code segment?

n = 1;
for ( ; n <= 5; )
cout << n << ' ';
n++;




1. 1 2 3 4 5

2. 1 1 1 ... and on forever

3. 2 3 4 5 6

4. 1 2 3 4

5. 2 3 4 5