To answer this question, you need to understand the concept of COMP-3, which is a binary-coded decimal (BCD) representation used in mainframe computers.

In COMP-3, each decimal digit is represented by a nibble (4 bits), and the sign is stored in the last nibble. The maximum length of a field defined using COMP-3 is determined by the number of bytes required to store the digits and the sign.

To calculate the maximum length, you need to consider the following:

- Each byte can store two decimal digits.
- The sign is stored in the last nibble, which requires an additional half byte.

Now, let's go through each option to determine the correct answer:

Option A) 10 Bytes - This option is correct. With 10 bytes, you can store 20 decimal digits and the sign (1/2 byte). This is the maximum length for a field defined using COMP-3.

Option B) 12 Bytes - This option is incorrect. With 12 bytes, you can store 24 decimal digits and the sign (1/2 byte), which exceeds the maximum length for a COMP-3 field.

Option C) 14 Bytes - This option is incorrect. With 14 bytes, you can store 28 decimal digits and the sign (1/2 byte), which exceeds the maximum length for a COMP-3 field.

Option D) 16 Bytes - This option is incorrect. With 16 bytes, you can store 32 decimal digits and the sign (1/2 byte), which exceeds the maximum length for a COMP-3 field.

Therefore, the correct answer is Option A) 10 Bytes. This option is correct because it represents the maximum length for a field defined using COMP-3, allowing you to store 20 decimal digits and the sign.