**Core Concept**
Low tension alternating current (LTAC) is a form of electrical current that can cause severe physiological effects due to its frequency and waveform. LTAC can interfere with the normal functioning of the nervous system, leading to muscle contractions and potentially life-threatening consequences.

**Why the Correct Answer is Right**
The main danger with LTAC is its ability to cause tetany, a condition characterized by repetitive muscle contractions. This occurs due to the stimulation of nerve fibers, which can lead to the release of neurotransmitters that trigger muscle contractions. LTAC can also disrupt the normal functioning of the heart, leading to arrhythmias and potentially cardiac arrest. The frequency of LTAC, typically between 50-60 Hz, is particularly effective at causing these effects due to its resonance with the human body's natural frequency.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to the topic of LTAC and its effects on the human body.
* **Option B:** While high tension alternating current (HTAC) is indeed more dangerous than LTAC, this option does not address the specific risks associated with LTAC.
* **Option C:** This option is incorrect because it does not accurately describe the main danger associated with LTAC.

**Clinical Pearl / High-Yield Fact**
It is essential for medical professionals to be aware of the risks associated with LTAC, particularly in patients who may be sensitive to electrical currents, such as those with pacemakers or other implantable devices.

**Correct Answer: C. Muscle contractions due to tetany.**