**Core Concept**
Posterior compartment syndrome occurs due to increased pressure within the posterior compartment of the leg, leading to ischemia and pain. The posterior compartment contains muscles responsible for ankle and foot movement, including the flexor digitorum longus, flexor hallucis longus, and tibialis posterior.

**Why the Correct Answer is Right**
Passive dorsiflexion of the foot stretches the muscles and tendons within the posterior compartment, increasing tension on the compromised structures and exacerbating pain. This phenomenon is known as the "dorsiflexion test" or "plantar fascia stretch test." The increased pain with passive movement indicates compartmental pressure and is a diagnostic clue for posterior compartment syndrome.

**Why Each Wrong Option is Incorrect**
* **Option A:** Passive inversion of the foot is less likely to cause pain in posterior compartment syndrome, as inversion primarily involves the lateral compartment.
* **Option B:** Passive plantarflexion of the foot may relieve pain in posterior compartment syndrome, as it reduces tension on the compromised muscles and tendons.
* **Option C:** Passive abduction of the foot is not a relevant movement in diagnosing posterior compartment syndrome, as it does not directly affect the posterior compartment muscles.

**Clinical Pearl / High-Yield Fact**
In posterior compartment syndrome, the "dorsiflexion test" can be a useful diagnostic tool, but it should be performed carefully to avoid exacerbating the condition. A positive test is indicated by pain with passive dorsiflexion of the foot, and it should be used in conjunction with other clinical findings to establish a diagnosis.

**Correct Answer: D. Passive dorsiflexion of the foot.**