**Core Concept**
The patient's condition, recurrent stone passage, is likely due to a metabolic disorder causing excessive formation of kidney stones. The primary concern is to restrict dietary components that contribute to stone formation, while maintaining essential nutrients.

**Why the Correct Answer is Right**
Calcium restriction is not the correct approach for this patient. In fact, calcium is crucial for bone health and can help prevent certain types of kidney stones, such as oxalate stones. By restricting calcium, the patient may actually increase their risk of oxalate stone formation. This is because calcium binds to oxalate in the gut, preventing its absorption and subsequent excretion in the urine, where it can contribute to stone formation.

**Why Each Wrong Option is Incorrect**
**Option A:** Protein restriction is not directly related to kidney stone formation. However, a high-protein diet can increase the excretion of oxalate and uric acid, both of which can contribute to stone formation. Restricting protein may not be the primary concern in this case.
**Option C:** A salt-restricted diet can help reduce the excretion of calcium in the urine, which may actually contribute to stone formation. Therefore, restricting salt is not the best approach for this patient.
**Option D:** Phosphate restriction may be beneficial in certain cases of kidney stone formation, such as in patients with primary hyperparathyroidism. However, in this case, the question does not specify a condition that would warrant phosphate restriction.

**Clinical Pearl / High-Yield Fact**
In patients with recurrent kidney stone formation, it's essential to consider the type of stone and the underlying metabolic disorder. A thorough evaluation, including laboratory tests and imaging studies, is necessary to determine the best dietary approach and prevent further stone formation.

**✓ Correct Answer: B. Calcium restriction**