**Core Concept**
The loop of Henle is a U-shaped structure within the nephron that plays a crucial role in the concentration and dilution of urine, as well as the regulation of electrolyte balance. The loop of Henle is composed of three sections: the descending limb, the ascending limb (with a thin and thick segment), and the hairpin turn.

**Why the Correct Answer is Right**
The long loop of Henle is characteristic of the juxtamedullary nephron, which is a type of nephron found in the renal cortex. The long loop of Henle extends deep into the renal medulla, allowing for a more efficient exchange of ions and water between the tubular fluid and the surrounding interstitium. This enables the kidney to concentrate or dilute the urine as needed, depending on the body's hydration status.

**Why Each Wrong Option is Incorrect**
* **Option A:** Cortical nephrons do not have long loops of Henle. They are located in the renal cortex and have shorter loops of Henle that do not penetrate the medulla.
* **Option B:** The outer stripe of the outer medulla contains a mixture of cortical and juxtamedullary nephrons, but not all nephrons in this region have long loops of Henle.
* **Option C:** The inner stripe of the outer medulla contains primarily cortical nephrons and a few juxtamedullary nephrons, but the majority of nephrons in this region do not have long loops of Henle.

**Clinical Pearl / High-Yield Fact**
The long loop of Henle is responsible for the countercurrent multiplication mechanism, which allows the kidney to concentrate or dilute the urine. This mechanism is essential for maintaining proper electrolyte balance and fluid status in the body.

**Correct Answer:** C. Juxtamedullary nephron.