**Core Concept**
Glucose-6-phosphatase deficiency leads to an impairment in the final step of glucose metabolism, resulting in the accumulation of glucose-6-phosphate in the liver. This triggers a series of metabolic byproducts, including the formation of pentose sugars, which are then converted into uric acid through the purine metabolism pathway.

**Why the Correct Answer is Right**
The correct answer, **A. More formation of pentose**, is due to the accumulation of glucose-6-phosphate in the liver. This triggers the pentose phosphate pathway, leading to the formation of excess pentose sugars. These pentose sugars are then converted into ribose-5-phosphate, which is a precursor for the synthesis of nucleotides. The breakdown of nucleotides results in the formation of uric acid, leading to hyperuricemia and gout.

**Why Each Wrong Option is Incorrect**
**Option B:** Decreased availability of glucose to tissues is incorrect because glucose-6-phosphatase deficiency primarily affects glucose release from the liver, not glucose availability to tissues. Tissues still receive glucose from other sources, such as gluconeogenesis and glycogen breakdown.

**Option C:** Increased accumulation of sorbitol is incorrect because glucose-6-phosphatase deficiency is related to glucose metabolism, not sorbitol metabolism. Sorbitol accumulation is associated with aldose reductase deficiency, a different enzyme deficiency.

**Option D:** Impaired degradation of free radicals is incorrect because glucose-6-phosphatase deficiency is not directly related to free radical metabolism. While oxidative stress may be a secondary consequence of impaired glucose metabolism, it is not the primary cause of hyperuricemia and gout in glucose-6-phosphatase deficiency.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that glucose-6-phosphatase deficiency can lead to a range of metabolic complications, including hyperuricemia, gout, and hypoglycemia. This is because the enzyme plays a critical role in maintaining normal glucose levels and preventing the accumulation of toxic byproducts.

**✓ Correct Answer: A. More formation of pentose**