An unbiased die with faces marked 1, 2, 3, 4, 5 and 6 is rolled four times, Out of four face values obtained, the probability that the minimum face value is not less than 2 and the maximum face value is not greater than 5, is
(a) 1 6/81
(b) 1/81
(c) 80/81
(d) 65/81