**Core Concept**
Hyperparathyroidism is characterized by excessive secretion of parathyroid hormone (PTH), leading to increased calcium levels and altered phosphate metabolism. The condition results in hypercalcemia, hypophosphatemia, and altered renal function, including changes in phosphate excretion.

**Why the Correct Answer is Right**
In hyperparathyroidism, the increased PTH levels stimulate the kidneys to reabsorb more phosphate, resulting in decreased phosphate excretion in the urine. This is a classic compensatory mechanism to maintain serum phosphate levels. The kidneys increase phosphate reabsorption in the proximal tubules, leading to reduced phosphate excretion. Consequently, the urine phosphate level does not decrease; instead, it may even increase due to the increased PTH levels.

**Why Each Wrong Option is Incorrect**
**Option A:** Normal alkaline phosphatase levels are not typically seen in primary hyperparathyroidism, as increased bone resorption leads to elevated alkaline phosphatase levels.
**Option C:** Increased calcium levels are a hallmark of hyperparathyroidism, resulting from the increased PTH-mediated bone resorption, increased renal calcium reabsorption, and increased intestinal calcium absorption.
**Option D:** Hypophosphatemia is a characteristic feature of hyperparathyroidism, resulting from the increased PTH-mediated phosphate excretion in the urine.

**Clinical Pearl / High-Yield Fact**
In cases of hyperparathyroidism, the presence of normal or elevated alkaline phosphatase levels, along with decreased phosphate excretion in the urine, can be misleading. A careful evaluation of the patient's clinical presentation, laboratory results, and imaging studies is essential to confirm the diagnosis.

**✓ Correct Answer: B. Decreased phosphate in urine**