**Core Concept**
The normal AV nodal delay refers to the time it takes for an electrical impulse to travel through the atrioventricular (AV) node, a critical structure in the heart's conduction system. This delay is crucial for ensuring proper coordination between atrial and ventricular contractions. The AV node acts as a relay station, delaying the impulse to allow for optimal filling of the ventricles.

**Why the Correct Answer is Right**
The normal AV nodal delay is approximately 100 milliseconds, but since the answer choices are not provided, let's discuss the general concept. This delay allows the ventricles to fill completely with blood before contraction, ensuring efficient pumping of blood. The AV node's delay is influenced by the autonomic nervous system, with sympathetic stimulation decreasing the delay and parasympathetic stimulation increasing it.

**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific answer choice, it's challenging to provide a detailed explanation, but any option significantly deviating from the normal physiological range would be incorrect.
**Option B:** Similarly, without the exact value, it's difficult to assess, but an option suggesting an abnormally short or long delay would not be accurate.
**Option C:** This option would be incorrect if it proposes a delay that does not align with the normal physiological range.
**Option D:** Any option that does not reflect the normal AV nodal delay would be incorrect.

**Clinical Pearl / High-Yield Fact**
Remember, the AV node's delay is crucial for heart function. Abnormalities in this delay can lead to various arrhythmias and conduction disorders. Understanding the normal delay is key to diagnosing and managing these conditions.

**Correct Answer:** Correct Answer: C. 100 ms