**Core Concept**
The management of ureteral calculi depends on the location, size, and composition of the stone, as well as the presence of associated complications such as hydronephrosis. In this scenario, a 10-mm calculus in the right lower ureter with proximal hydroureteronephrosis requires a minimally invasive approach to avoid further complications.

**Why the Correct Answer is Right**
Ureteroscopic retrieval is the preferred treatment for lower ureteral calculi due to its high success rate and minimal invasiveness. The procedure involves passing a flexible or semi-rigid ureteroscope through the bladder and into the ureter to visualize the stone. A basket or laser is then used to retrieve the stone. This approach is particularly effective for smaller stones (less than 2 cm) and those located in the lower ureter, as in this case. The use of ureteroscopy allows for direct visualization and manipulation of the stone, reducing the risk of complications associated with more invasive procedures.

**Why Each Wrong Option is Incorrect**
**Option A:** Extracorporeal shock wave lithotripsy (ESWL) is generally reserved for larger stones (greater than 2 cm) or those located in the upper ureter, as the success rate decreases with smaller stones and lower ureteral location. ESWL may also cause significant discomfort and has a higher risk of complications, including ureteral perforation.

**Option B:** Percutaneous nephrolithotomy (PCNL) is typically reserved for larger stones (greater than 2 cm) that are located in the renal pelvis or upper ureter. PCNL involves making a small incision in the back to insert a scope and instruments to break up the stone, which is then removed. This approach is more invasive and carries a higher risk of complications than ureteroscopic retrieval.

**Option C:** Open ureterolithotomy is a more invasive surgical approach that involves making a large incision in the abdomen to access the ureter. This procedure is generally reserved for cases where other treatments have failed or are not feasible due to the location and size of the stone, as well as the presence of associated complications.

**Clinical Pearl / High-Yield Fact**
When managing ureteral calculi, it's essential to consider the location, size, and composition of the stone, as well as the presence of associated complications. Ureteroscopic retrieval is a minimally invasive and highly effective approach for smaller stones (less than 2 cm) located in the lower ureter, such as in this case.

**✓ Correct Answer: D. Ureteroscopic retrieval**