**Core Concept**
The question requires knowledge of pharmacokinetics and pharmacodynamics in the context of hepatic and renal failure. Muscle relaxants can be affected by impaired liver function, which affects metabolism, and impaired kidney function, which affects excretion.

**Why the Correct Answer is Right**
In hepatic and renal failure, succinylcholine is not the preferred muscle relaxant due to its potential for severe hyperkalemia. Rocuronium, a non-depolarizing muscle relaxant, is often chosen because it has a rapid onset of action and does not rely on hepatic or renal elimination. Its metabolites are excreted in the bile, but the parent compound is primarily excreted by the kidneys. However, its hepatic metabolism is minimal, making it a safer choice in patients with compromised liver function.

**Why Each Wrong Option is Incorrect**
* **Option A:** Pancuronium is a non-depolarizing muscle relaxant with a longer duration of action. It is primarily excreted by the kidneys, making it a less desirable choice in patients with renal failure.
* **Option B:** Vecuronium is another non-depolarizing muscle relaxant, but it undergoes significant hepatic metabolism, which makes it less ideal in patients with hepatic impairment.
* **Option C:** Atracurium is a non-depolarizing muscle relaxant that undergoes Hoffman elimination, a non-enzymatic process that is independent of liver and kidney function. However, its use is not typically preferred in acute settings due to its slower onset of action and longer duration.

**Clinical Pearl / High-Yield Fact**
In patients with hepatic and renal failure, choose muscle relaxants with minimal hepatic metabolism and primarily renal excretion, such as rocuronium or cisatracurium.

**Correct Answer: C. Atracurium is actually incorrect, the correct answer is actually not listed. The best answer choice for the question is: Cisatracurium.**