One turn of the helix in a B-form DNA is approximately of the length

Most hydrated and most stable form of DNA is known as:

Each step of ascent of a strand of DNA:

I. is represented by a pair of bases
II. the strand turns 360
III. the rise per base pair is 3.4 nm

1. Only II is correct
2. Only I and II are correct
3. only II and III are correct
4. I, II and III are correct