How to choose the correct size of plastic spiral coil for your book?

How to choose the correct size of plastic spiral coil for your book?

Avialable Pitch as following:

1). 5:1 Pitch; 58 or 59 loops for A4 SIZE;

2). 4:1 Pitch; 48 or 49 loops for A4 SIZE;

3). 3:1 Pitch; 35 or 38 loops for A4 SIZE;4). 2:1 Pitch; 21 or 23 loops for A4 SIZE.