Demultiplexer (DEMUX) function clarification: Evaluate the statement — “A demultiplexer accepts a dual (two-line) data input value and routes it to one of several outputs.”

Introduction / Context:
Demultiplexers are essential for distributing a single data stream to one of many destinations under control of select lines. Confusing DEMUX behavior with multiplexers (which select one of many inputs) is a common beginner error. This item tests whether you can articulate the DEMUX direction of data flow correctly.

Given Data / Assumptions:

• A DEMUX has one data input, multiple outputs, and select lines.
• Select inputs determine which single output line receives the input data.
• Nonselected outputs are typically forced low, high, or left inactive per implementation.

Concept / Approach:
By definition, a 1-to-2^n DEMUX takes one data input (not “dual”) and, based on n select lines, routes that input to exactly one of the 2^n outputs. The statement claiming a “dual input data value” incorrectly describes the DEMUX’s data interface; dual inputs relate more to differential signaling or to a 2-to-1 MUX, not to a DEMUX.

Step-by-Step Solution:

Verification / Alternative check:
Consult a truth table for a 1-to-8 DEMUX. For each select combination, exactly one Yk mirrors the single data input D; all others are inactive. There is no “dual” data input.

Why Other Options Are Wrong:

• Correct: Not correct because the DEMUX does not require dual data inputs.
• Correct only for 1-to-2 devices: Even 1-to-2 DEMUXs still have one data input, not two.
• Depends on the number of select lines: Select lines affect fan-out, not number of data inputs.
• True for time-division multiplexing only: TDM is a system-level concept, unrelated to the single-input DEMUX definition.

Common Pitfalls:
Mixing up MUX and DEMUX; assuming more outputs implies more data inputs; overlooking that select lines carry address information, not payload data.

Final Answer:
Incorrect