Signal level behavior in digital systems: Digital logic requires clearly defined discrete voltage levels (LOW and HIGH) and transitions between them to represent binary information. Assess this requirement.

Introduction / Context:
Digital electronics uses two distinct logic levels to represent binary 0 and 1. Reliable interpretation of these levels, along with controlled transitions between them, underpins noise margins, timing analysis, and interoperability among logic families.

Given Data / Assumptions:

• Logic families define VIH, VIL, VOH, VOL thresholds.
• Signals switch between these regions with finite rise/fall times.
• Receivers sample or latch the logic state at defined times.

Concept / Approach:
To encode bits, voltages must occupy one of two acceptable windows (LOW or HIGH). Transitions between these windows carry information at clock/sample boundaries. Proper edge rates and hysteresis (e.g., Schmitt triggers) ensure signals do not linger in undefined regions, preventing metastability and false switching.

Step-by-Step Solution:

Verification / Alternative check:
Examine a CMOS input: if VIN is within undefined ranges, logic is ambiguous. Ensuring transitions occur and levels settle into valid windows is mandatory for reliable operation.

Why Other Options Are Wrong:
“Incorrect” denies binary encoding fundamentals. Claims that it applies only to TTL or only at DC misunderstand how CMOS and TTL both define valid level ranges and rely on transitions.

Common Pitfalls:
Ignoring ground bounce, crosstalk, or slow edges; failing to meet setup/hold times so that transitions are not sampled correctly.

Final Answer:
Correct