**Core Concept**
The apparent volume of distribution (Vd) of a drug is a pharmacokinetic parameter that estimates the volume of body fluids in which a drug is distributed. It is calculated by dividing the total amount of drug in the body by the plasma concentration. A Vd that exceeds the total body fluid volume suggests that the drug is widely distributed beyond the bloodstream, into tissues and other body compartments.

**Why the Correct Answer is Right**
When a drug is sequestrated in body tissues, it is concentrated in specific tissues or organs, such as fat, muscle, or liver. This leads to a higher concentration of the drug in these tissues compared to the plasma. As a result, the total amount of drug in the body is greater than the plasma concentration, resulting in a Vd that exceeds the total body fluid volume. This phenomenon is often observed with lipophilic (fat-soluble) drugs, which tend to accumulate in fatty tissues.

**Why Each Wrong Option is Incorrect**

**Option B:** Slow elimination from the body does not directly affect the Vd. While a drug with slow elimination may have a higher concentration in the body, it does not necessarily imply a higher Vd.

**Option C:** Poor solubility in plasma may affect the drug's absorption, distribution, or metabolism, but it does not directly influence the Vd.

**Option D:** Poor binding to plasma protein may lead to a higher free fraction of the drug in the plasma, but it does not necessarily result in a Vd that exceeds the total body fluid volume.

**Clinical Pearl / High-Yield Fact**
Drugs with a high Vd, such as lipid-soluble anesthetics, may require larger doses to achieve therapeutic effects, as they are widely distributed in body tissues. However, this also increases the risk of toxicity, as the drug concentration in these tissues may exceed therapeutic levels.

**✓ Correct Answer: A. Sequestrated in body tissues**