Correct option is C
In BCD (Binary-Coded Decimal) code, each digit is typically represented by a 4-bit binary number, allowing for 16 possible combinations (from 0000 to 1111). However, BCD is often used to represent only the decimal digits 0-9, leaving 6 unused combinations. Therefore, the maximum possible character set size for BCD can be extended to 64 characters if using 6 bits instead of 4, as extended BCD can encode uppercase letters, numbers, and some special characters.
