**Core Concept**
The question is testing knowledge of the effects of snake venom on the human body, specifically the neurological effects of certain snake venoms. The underlying principle involves the disruption of normal neuromuscular function.

**Why the Correct Answer is Right**
The correct answer is related to the venom's effect on the nervous system, specifically on the neuromuscular junction. Certain snake venoms, like those from cobras, kraits, and taipans, contain neurotoxins that can bind to **nicotinic acetylcholine receptors** at the neuromuscular junction, preventing acetylcholine from binding and thus inhibiting muscle contraction. This leads to progressive muscle paralysis.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the venom's primary effect in this scenario is not on the heart.
**Option B:** This option is also incorrect as the primary issue is not with the skeletal muscle itself but with the neuromuscular transmission.
**Option D:** This option is incorrect because, although some snake venoms can affect blood clotting, the primary symptom described here is muscle paralysis, not a coagulopathy.

**Clinical Pearl / High-Yield Fact**
It's crucial to remember that neurotoxic snake venoms can cause respiratory failure due to paralysis of the diaphragm and other respiratory muscles, making prompt medical intervention critical.

**Correct Answer:** D. neuromuscular junction