**Core Concept**
A torn medial meniscus is a common injury in the knee, often resulting from twisting or bending movements that cause the meniscus to tear. The medial meniscus is a cartilaginous structure that provides cushioning and stability to the knee joint. A torn medial meniscus can lead to various clinical manifestations, including pain, instability, and locking.

**Why the Correct Answer is Right**
Excessive forward glide of the tibia is not a typical feature of a torn medial meniscus. This is because the medial meniscus is located on the medial aspect of the knee joint and is not directly involved in the anterior-posterior movement of the tibia. In contrast, a torn anterior cruciate ligament (ACL) or a meniscal injury in the anterior horn of the meniscus may cause excessive forward glide due to the disruption of the normal stabilizing structures. A torn medial meniscus is more likely to cause pain, locking, and giving way due to the mechanical obstruction caused by the torn meniscus.

**Why Each Wrong Option is Incorrect**

**Option B:** Giving way is a common symptom of a torn medial meniscus, as the torn meniscus can cause mechanical obstruction and instability in the knee joint.

**Option C:** Locking is a characteristic feature of a torn meniscus, as the torn meniscus can become caught in the joint and cause mechanical obstruction, leading to a feeling of locking or catching.

**Option D:** Mc. Murray's sign, also known as the McMurray test, is a clinical test used to diagnose a torn meniscus. The test involves flexing the knee and then extending it while applying pressure on the meniscus. A positive test result is indicative of a torn meniscus.

**Clinical Pearl / High-Yield Fact**
A torn medial meniscus can be diagnosed clinically using the McMurray test, and a positive test result is highly suggestive of a meniscal tear. However, imaging studies such as MRI are often necessary to confirm the diagnosis and rule out other causes of knee pain and instability.

**Correct Answer:**
✓ Correct Answer: A. Excessive forward glide