JEE Math Practice Question

Four numbers are chosen at random (without replacement) from the set $$\left\{ {1,2,3,....20} \right\}.$$ Statement - 1: The probability that the chosen numbers when arranged in some order will form an AP is $${1 \over {85}}.$$ Statement - 2: If the four chosen numbers form an AP, then the set of all possible values of common difference is $$\left( { \pm 1, \pm 2, \pm 3, \pm 4, \pm 5} \right).$$

1. A.Statement - 1 is true, Statement - 2 is true; Statement - 2 is not a correct explanation for Statement - 1.
2. B.Statement - 1 is true, Statement - 2 is false.
3. C.Statement - 1 is false, Statement -2 is true.
4. D.Statement - 1 is true, Statement - 2 is true; Statement - 2 is a correct explanation for Statement - 1.