Correct option is D

Step 3: Eliminate Incorrect Options
1. 3 × 9 Multiplexer: Incorrect, as multiplexers select one input line based on control lines, not priority encoding.
2. Decimal to BCD Converter: Incorrect, as the given circuit does not convert decimal inputs to BCD format.
3. Octal to Binary Encoder: Incorrect, as this does not involve prioritizing input lines. It only encodes any active input into a binary representation.
4. Priority Encoder: Correct, as the circuit prioritizes inputs and outputs a binary representation of the highest-priority input.
Information Booster:
1. Priority Encoder:
· Outputs the binary code of the highest-priority active input.
· Includes additional logic to handle cases where multiple inputs are active simultaneously.
2. Applications of Priority Encoders:
· Interrupt controllers in microprocessors.
· Data selection in communication systems.
Additional Knowledge:
· A standard encoder does not prioritize inputs; it simply encodes any active input.
· A multiplexer routes one of many inputs to a single output based on select lines.
· Decimal to BCD is used to convert decimal digits into binary-coded decimal format.