Digital clock counter behavior (hours vs. minutes/seconds): In common clock designs, the hours section is implemented so that, unlike the seconds and minutes sections, it never goes to ________.

Introduction / Context:
Digital clocks can be realized in 12-hour or 24-hour formats. The seconds and minutes sections are typically modulo-60 counters that cycle from 00 through 59 and then back to 00. The hours section, however, is often constrained differently depending on the format: 1–12 for 12-hour clocks (with AM/PM) and 00–23 for 24-hour clocks. This question focuses on the common 12-hour display behavior.

Given Data / Assumptions:

• We consider a 12-hour clock display (typical in consumer devices).
• Seconds/minutes roll from 59 to 00.
• Hours should present human-friendly values 1 to 12, never “00.”
• AM/PM toggles at the 11→12 rollover.

Concept / Approach:
In a 12-hour implementation, the hours counter is not a simple BCD decade pair that reaches 00. Instead, it implements a modulo-12-with-offset sequence: 12, 1, 2, ... 11, 12, 1, ... This avoids the “00” hour on the display. That difference is what makes the hours section distinct from seconds/minutes, which do display 00 at rollover.

Step-by-Step Solution (Reasoning):

Verification / Alternative check:
Schematic/HDL implementations commonly detect 12→1 and 11→12 boundaries and prevent 00 from appearing on the hour display; testbenches show that at midnight/noon, the hour shows 12, not 00.

Why Other Options Are Wrong:

Common Pitfalls:
Implementing hours as a plain BCD pair resulting in 00 on rollover; forgetting to handle 12→1 and AM/PM toggling correctly.

Final Answer:
the 0 state