**Core Concept**
Arsenic toxicity is a condition resulting from exposure to high levels of arsenic, a metalloid element that can cause widespread cellular damage. The pathophysiology of arsenic toxicity involves the disruption of cellular metabolism, DNA damage, and the activation of various signaling pathways that lead to cellular death.

**Why the Correct Answer is Right**
The correct answer is a feature of arsenic toxicity due to its ability to bind to thiol groups in proteins, leading to the inhibition of various enzymes and the disruption of cellular metabolism. Arsenic also causes oxidative stress by generating reactive oxygen species (ROS), which damage cellular components and contribute to the development of various health problems. Additionally, arsenic has been shown to cause DNA damage, including the formation of adducts and mutations, which can lead to cancer.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while arsenic can cause gastrointestinal symptoms, such as nausea and vomiting, this is not a specific feature of arsenic toxicity.
**Option B:** This option is incorrect because arsenic toxicity is not typically associated with respiratory failure, although it can cause cardiovascular and neurological symptoms.
**Option C:** This option is incorrect because while arsenic can cause skin lesions, such as hyperpigmentation and hyperkeratosis, this is not a specific feature of arsenic toxicity.

**Clinical Pearl / High-Yield Fact**
Arsenic toxicity can be prevented by avoiding exposure to contaminated water and food sources, as well as by wearing protective clothing and equipment when handling arsenic-containing substances.

**Correct Answer:** B. Mees' lines are a feature of arsenic toxicity.