**Core Concept**
Fasciotomy is a surgical procedure involving the incision of fascia, a layer of connective tissue surrounding muscles and other structures. The goal of fasciotomy is to relieve pressure and tension in the affected area, typically in cases of compartment syndrome or severe swelling. In this procedure, the surgeon must carefully select which layers of tissue to cut to achieve the desired outcome.

**Why the Correct Answer is Right**
During a fasciotomy, the surgeon typically cuts through the skin and the superficial fascia, which is the layer of tissue just beneath the skin. The deep fascia, a more fibrous layer that surrounds the muscles, is also incised to access the muscles and relieve pressure. However, the muscles themselves are not cut during a fasciotomy; instead, the surgeon may release the tension within the muscle compartments by cutting the deep fascia that surrounds them. This approach helps to preserve muscle function and minimize damage.

**Why Each Wrong Option is Incorrect**
**Option A:** The skin is indeed cut during a fasciotomy to access the underlying tissues. This is a necessary step to allow the surgeon to visualize and manipulate the deeper structures.
**Option B:** The superficial fascia is also typically cut during a fasciotomy to facilitate access to the deeper tissues. This layer is usually incised to allow the surgeon to reach the deep fascia and the muscles.
**Option C:** While the deep fascia is cut during a fasciotomy, this is not because it is a "cut" in the same sense as the skin or superficial fascia; rather, it is a planned incision to relieve pressure and access the muscles.

**Clinical Pearl / High-Yield Fact**
When performing a fasciotomy, the surgeon must carefully balance the need to relieve pressure and tension in the affected area with the need to preserve muscle function and minimize damage. This requires a thorough understanding of the anatomy and a delicate touch, as well as a clear plan for managing the patient's care post-operatively.

**✓ Correct Answer: D. Muscles. Muscles are not cut during a fasciotomy.**