The property which a set of rational numbers have, is :
1. If x is a rational number, only one of the following is true (i) x<0 (ii) x=0 (iii) x>0
2. If x any y are any tow rational numbers, only one of the following is true (i) xy
3. x,y, z are three rational numbers. If x<y and y<z then x<z
4. All of the above