**Core Concept**
Zero-order kinetics refers to a type of pharmacokinetic model where the rate of drug elimination is constant and independent of the drug concentration. This occurs when the elimination process is saturated, often due to a high dose or a condition where the enzyme responsible for metabolism is overwhelmed.

**Why the Correct Answer is Right**
In zero-order kinetics, the rate of elimination is constant, regardless of the plasma concentration. This is in contrast to first-order kinetics, where the rate of elimination is directly proportional to the plasma concentration. The liver's cytochrome P450 enzymes can become saturated at high drug concentrations, leading to zero-order kinetics. This results in a linear relationship between the dose and the area under the plasma concentration-time curve (AUC).

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe zero-order kinetics. While it's true that enzyme saturation can occur, it's not the defining characteristic of zero-order kinetics.
**Option B:** This option is incorrect because it's a feature of first-order kinetics, not zero-order kinetics. The rate of elimination is directly proportional to the concentration in first-order kinetics.
**Option C:** This option is incorrect because it's a general statement about drug metabolism, but it doesn't specifically address the characteristics of zero-order kinetics.

**Clinical Pearl / High-Yield Fact**
When dealing with drugs that exhibit zero-order kinetics, it's essential to be aware of the potential for non-linear pharmacokinetics. This can result in a disproportionate increase in AUC and toxicity with increasing doses.

**Correct Answer: C.**