Four numbers are chosen at random (without replacement) from the set {1,2,3, ..., 20}.
Statement I The probability that the chosen numbers when arranged in some order will form an AP is 1/85.
Statement II If the four chosen numbers form an AP, then the set of all possible values of common difference is {±1, ±2, ±3, ±4, ±5].
(a) Statement I is true, Statement ll is true; Statement II is a correct explanation for Statement I
(b) Statement I is true, Statement II is true; Statement ll is trot a correct explanation for Statement I
(c) Statement I is true, Statement II is false
(d) Statement I is false, Statement II is true
