A cubical die is thrown 9 times and the numbers obtained are written as a 9 digit number. The probability that the number (A) begins with 246 is `1/6^3` (B) ends with 135 is `1/6^3` (C) begins with 246 and ends with 135 is `1/6^6` (D) begins with 248 or ends with 135 is `431/6^6`