**Core Concept**
The quadriceps femoris muscle is a group of four muscles (rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius) that work together to straighten the knee joint, extending the leg. This is achieved through the contraction of the quadriceps femoris muscle, which pulls the patella (kneecap) upward and straightens the knee.

**Why the Correct Answer is Right**
In case of paralysis of the quadriceps femoris muscle, the ability to extend the knee joint would be compromised. The quadriceps femoris muscle plays a crucial role in knee extension, and its paralysis would lead to weakness in this movement. This is because the quadriceps femoris muscle acts on the patella, which in turn acts on the tibia (shin bone) to extend the knee joint. The paralysis of the quadriceps femoris muscle would result in an inability to fully straighten the knee, making it difficult to perform movements that require knee extension.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because paralysis of the quadriceps femoris muscle would not affect hip flexion, which is primarily performed by the iliopsoas muscle.
**Option B:** This option is incorrect because paralysis of the quadriceps femoris muscle would not affect ankle dorsiflexion, which is primarily performed by the tibialis anterior muscle.
**Option C:** This option is incorrect because paralysis of the quadriceps femoris muscle would not affect hip abduction, which is primarily performed by the gluteus medius muscle.

**Clinical Pearl / High-Yield Fact**
Remember that the quadriceps femoris muscle plays a critical role in knee extension, and its paralysis can lead to significant weakness in this movement. This is often seen in patients with quadriceps weakness due to conditions such as stroke, spinal cord injury, or peripheral nerve injury.

**Correct Answer:** C.