Given that each tick represents 1. The numbers on the right of 0 are positiv and on the left of 0 are negative. SInce 2 is positive, 2 lies on the right side of 0.
Since each tick represents 1, the first tick represents 0+1 = 1.
Now, the second tick represents 0 + 2 = 2. The second tick on the right of 0 denoted as S.
The correct option is S.