Based on the paragraph given below answer the following question:The traditional methods of combinational circuits involve simplification and realization using gates. Using these methods, complex functions have been integrated and are easily available in IC form. There is an attractive array of devices like a multiplexer, demultiplexer, decoders, comparators, parity generators/checkers, which significantly reduce IC package count thereby reducing the system cost. The system design is greatly simplified because the laborious and time-consuming simplification methods are generally not required with these devices. This also improves the reliability of the system by reducing the number of external wired connections. But they have some limitations as well. Different memories like ROM, PROM can also be used to implement combinational circuits without much simplification.In a BCD Subtractor if the sum of minuend and the nine’s complement of the subtrahend is not a valid BCD Code, then which binary number is added to the sum to get the correct answer?

• A. 1000
• B. 0001
• C. 0110
• D. 0111