Retriggerable monostable multivibrator — identify what is NOT an inherent characteristic. Select the option that does not generally define retriggerable monostables across families.

Introduction / Context:
This item checks whether you can distinguish universal characteristics of retriggerable monostables from package- or family-specific features. The focus is on traits that are always true vs traits that may be true only for particular ICs.

Given Data / Assumptions:

• We consider behavior and construction across common logic families (TTL/CMOS).
• Terms like "dual" can describe a package option, not a fundamental property.

Concept / Approach:
Retriggerability describes timing behavior: new triggers extend the active pulse. Whether an IC is "dual" (two monostables per package) or uses a particular reset polarity varies by part number and family. External timing components are also typical and not unique to retriggerable devices.

Step-by-Step Reasoning:

Verification / Alternative check:
Some retriggerable parts are single (one per package), others are dual. Therefore "dual" is not universally characteristic.

Why Other Options Are Wrong:

• Active-HIGH reset: many parts provide a reset; polarity can vary, but a reset that halts timing is characteristic behavior broadly.
• No internal timing resistor: timing typically uses external R and C in both retriggerable and non-retriggerable families.
• Extends the pulse if retriggered: this is the very definition of retriggerable behavior.
• none of the above: incorrect because at least one option (dual) is not inherent.

Common Pitfalls:

• Assuming a datasheet feature of a specific IC is universal to all retriggerables.

Final Answer:
It is a dual multivibrator.