**Core Concept**
The question is testing the knowledge of a clinical entity associated with kidney stones, specifically a triad of symptoms that occurs in patients with renal colic. This clinical entity is related to the anatomy and physiology of the urinary system.

**Why the Correct Answer is Right**
The triad of renal colic, swelling in the loin which disappears after passing urine is called the "acute nephrolithiasis" or more specifically, "flank mass" associated with renal colic. This is because the loin swelling is due to the inflammation of the perirenal fat and the surrounding tissues caused by the obstruction of the urinary tract by a stone. The swelling disappears after passing urine as the obstruction is relieved. This condition is often caused by the passage of a kidney stone through the urinary tract.

**Why Each Wrong Option is Incorrect**
**Option A:** Not relevant to the clinical entity described in the question.
**Option B:** Refers to a different clinical entity, specifically a type of kidney damage caused by toxins.
**Option C:** Not a recognized medical term describing the triad of symptoms mentioned in the question.

**Clinical Pearl / High-Yield Fact**
It is essential for students to remember that loin swelling in patients with renal colic is due to perirenal inflammation, which resolves after the passage of the stone. This clinical correlation is crucial for differentiating between various causes of loin pain.

**Correct Answer:** C. Flank mass associated with renal colic.