Question 2. (12 pts) Consider the following set of pre and postconditions for a method: // Precondition: "aChar" is a character from the set // of characters defined by the following ranges: // A 'Z', 'a' 'z', 'O' ...'9' Postcondition: The value returned by the function // is true if "aChar" is a valid octal digit; // otherwise the value returned by the function is false. boolean isOctDigit(char aChar) { } What is the result of the following call: isOctDigit('-'); Select one: O true false null The result is undefined An exception is thrown None of the above