**Core Concept**
The 'boiled lobster' appearance is a clinical presentation associated with hypocalcemia, which can be caused by various factors, including poisoning. This appearance is due to the tetany and muscle cramps that result from low calcium levels.

**Why the Correct Answer is Right**
The correct answer is likely related to a condition that causes hypocalcemia. One such condition is **calcium channel blocker poisoning**, which can lead to a decrease in serum calcium levels, resulting in the characteristic 'boiled lobster' appearance due to tetany and muscle cramps. This occurs because calcium channel blockers interfere with the influx of calcium ions into muscle cells, leading to muscle weakness and cramping.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not directly relate to the 'boiled lobster' appearance. While **barbiturate poisoning** can cause various systemic effects, it is not typically associated with hypocalcemia or this specific clinical presentation.

**Option B:** This option is incorrect because **organophosphate poisoning** primarily affects the nervous system, causing cholinergic crisis, and is not typically associated with hypocalcemia or the 'boiled lobster' appearance.

**Option C:** This option is incorrect because **salicylate poisoning** can cause various systemic effects, including metabolic acidosis and respiratory alkalosis, but it is not typically associated with hypocalcemia or the 'boiled lobster' appearance.

**Option D:** This option is incorrect because **digoxin poisoning** can cause cardiac arrhythmias and other systemic effects, but it is not typically associated with hypocalcemia or the 'boiled lobster' appearance.

**Clinical Pearl / High-Yield Fact**
The 'boiled lobster' appearance is a classic clinical presentation of hypocalcemia, which can be caused by various factors, including poisoning. It is essential to recognize this presentation and investigate the underlying cause promptly to provide appropriate treatment.

**Correct Answer: C. Calcium channel blocker poisoning**