Correct option is C
The first step in the aerobic glycolysis pathway is the conversion of glucose to glucose 6-phosphate. This reaction is catalyzed by the enzyme hexokinase and requires ATP. This phosphorylation traps glucose inside the cell and marks the beginning of the glycolytic process, which eventually leads to the formation of pyruvate under aerobic conditions.
Explanation of options: (a) Fructose 6-phosphate – This is an intermediate in the glycolytic pathway, formed after glucose 6-phosphate. It is not the initial step. (b) Phospho-fructokinase – This is an enzyme, not a metabolite. It catalyzes a later step in glycolysis where fructose 6-phosphate is converted to fructose 1,6-bisphosphate. (c) Glucose 6-phosphate – This is the correct answer. It is the product of the first step of glycolysis, formed from glucose by the action of hexokinase using one molecule of ATP. (d) Pyruvate – Pyruvate is the end product of glycolysis, not the beginning. It is formed after multiple intermediate steps and is used in the TCA cycle under aerobic conditions.