**Core Concept**
Glycolysis is a crucial metabolic pathway that converts glucose into pyruvate, generating energy for the cell. This process is tightly regulated by various enzymes to ensure proper energy production and prevent excessive glucose consumption.

**Why the Correct Answer is Right**
The regulation of glycolysis involves several key enzymes, including hexokinase (or glucokinase in the liver), phosphofructokinase-1 (PFK-1), and pyruvate kinase. These enzymes control the flux through the glycolytic pathway by modulating the concentrations of glycolytic intermediates. For example, PFK-1 is allosterically inhibited by high ATP and citrate levels, signaling low energy status, and is activated by AMP, indicating a need for energy production.

**Why Each Wrong Option is Incorrect**
**Option A:** Glucose-6-phosphate dehydrogenase is not a glycolytic enzyme but rather a key enzyme in the pentose phosphate pathway, which generates NADPH and pentoses from glucose-6-phosphate.
**Option B:** Pyruvate carboxylase is not a glycolytic enzyme but rather a key enzyme in gluconeogenesis, which generates glucose from pyruvate, lactate, or other non-carbohydrate carbon sources.
**Option C:** Phosphoglycerate kinase is indeed a glycolytic enzyme, catalyzing the conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate, generating ATP in the process.

**Clinical Pearl / High-Yield Fact**
Inhibitors of glycolytic enzymes, such as 2-deoxyglucose, have been explored as potential anticancer agents, as they can selectively deplete energy stores in cancer cells, which are often more reliant on glycolysis than normal cells.

**Correct Answer:** B. Pyruvate carboxylase.