**Core Concept**
The anterior cruciate ligament (ACL) is a key component of the knee joint, providing stability and preventing excessive movement. The **ACL** plays a crucial role in preventing anterior translation of the tibia relative to the femur. This ligament is essential for maintaining knee joint integrity.

**Why the Correct Answer is Right**
The correct answer is related to the function of the **ACL** in preventing anterior tibial translation, which is a critical aspect of knee stability. The **ACL** achieves this by connecting the femur to the tibia and resisting anterior movement of the tibia.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because the **ACL** does not primarily prevent hyperextension.
**Option B:** Incorrect as the **ACL** is not primarily involved in preventing varus or valgus stress.
**Option C:** Incorrect because while the **ACL** does contribute to rotational stability, this is not its primary function.

**Clinical Pearl / High-Yield Fact**
A memorable point is that **ACL** injuries often occur during activities that involve sudden stops or changes in direction, such as soccer or basketball.

**Correct Answer:** D. Anterior dislocation of tibia.