**Core Concept**
The subtalar joint is a complex hinge joint in the foot that plays a crucial role in facilitating various movements such as inversion and eversion. It is formed by the articulation between the talus and calcaneus bones.

**Why the Correct Answer is Right**
Inversion and eversion of the foot occur primarily due to the movement of the talus bone within the subtalar joint. When the foot inverts, the talus bone moves medially (towards the midline of the body), and when it everts, the talus bone moves laterally (away from the midline). The subtalar joint's unique anatomy allows for this range of motion, which is essential for balance and movement during walking, running, and other activities.

**Why Each Wrong Option is Incorrect**
**Option B:** The tibiotalar joint, also known as the ankle joint, primarily facilitates dorsiflexion and plantarflexion movements of the foot. It is not responsible for inversion and eversion.
**Option C:** The inferior tibiofibular joint is a syndesmosis that provides stability to the ankle joint. It does not contribute to the movement of the foot during inversion and eversion.
**Option D:** The tarso-metatarsal joint is a complex joint that facilitates movements between the tarsal bones and the metatarsal bones. While it does play a role in foot movement, it is not primarily responsible for inversion and eversion.

**Clinical Pearl / High-Yield Fact**
The subtalar joint is often overlooked in clinical practice, but understanding its function is crucial for diagnosing and managing conditions such as flat feet, high arches, and peroneal tendonitis.

**✓ Correct Answer: A. Subtalar joint**