**Core Concept**
Enzyme specificity refers to the ability of an enzyme to catalyze a particular chemical reaction with a specific substrate, while ignoring other structurally similar molecules. This specificity is crucial for the efficiency and accuracy of biochemical processes within living organisms.

**Why the Correct Answer is Right**
The correct answer is related to the concept of the "lock-and-key" model of enzyme-substrate interaction. In this model, the enzyme's active site is shaped like a key, which fits into the substrate's binding site, allowing for efficient catalysis. The shape and chemical properties of the active site determine the enzyme's specificity for a particular substrate. Enzymes with high specificity have a precise fit between their active site and the substrate, allowing for minimal non-specific binding and optimal catalytic activity.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the mechanism of enzyme specificity.
**Option B:** This option is incorrect because it refers to the concept of enzyme promiscuity, where an enzyme can catalyze multiple reactions, rather than specificity.
**Option C:** This option is incorrect because it refers to the concept of enzyme inhibition, which is a separate phenomenon from enzyme specificity.

**Clinical Pearl / High-Yield Fact**
Enzyme specificity is a critical determinant of an enzyme's function and can be influenced by various factors, including pH, temperature, and the presence of inhibitors or activators. Understanding enzyme specificity is essential for the rational design of drugs and the interpretation of laboratory results.

**Correct Answer: D. Substrate shape and chemical properties.**