Explanation:

A binary full-subtractor is a combinational circuit that is used to subtract two binary numbers, taking into account a borrow input. It consists of two half-subtractors and one OR gate, which makes option B the correct answer.

Half-Subtractor:
A half-subtractor is a combinational circuit that has two inputs (minuend and subtrahend) and two outputs (difference and borrow). It subtracts the subtrahend from the minuend and produces the difference and the borrow.

Binary Full-Subtractor:
A binary full-subtractor is a circuit that can subtract two bits, along with a borrow input. It takes three inputs: minuend bit (A), subtrahend bit (B), and the borrow input (Bin). It produces two outputs: difference bit (D) and borrow output (Bout).

Functionality:
The binary full-subtractor works by using two half-subtractors in a cascaded manner. The first half-subtractor takes the minuend bit (A), subtrahend bit (B), and the borrow input (Bin) as inputs and produces the first difference bit (D1) and the first borrow output (Bout1).

The second half-subtractor takes the first difference bit (D1), subtrahend bit (B), and the borrow output from the first half-subtractor (Bout1) as inputs and produces the final difference bit (D) and the final borrow output (Bout).

The OR gate is used to combine the borrow outputs from both half-subtractors (Bout1 and Bout) to produce the final borrow output (Bout).

Advantages of using a Full-Subtractor:
- The full-subtractor can subtract any binary numbers with the borrow input taken into account.
- It is a versatile circuit that can be used in various arithmetic and logical operations.
- It can be easily implemented using basic logic gates, such as AND, OR, and XOR gates.
- The cascaded structure allows for efficient subtraction of multiple bits.

In conclusion, a binary full-subtractor consists of two cascaded half-subtractors and one OR gate, making option B the correct answer.