**Core Concept**
Pain and temperature sensation in the human body is mediated by specific types of nerve fibers that transmit signals to the brain through the spinal cord. This sensation is crucial for protecting the body from harm and is often associated with the transmission of nociceptive signals.

**Why the Correct Answer is Right**
The correct answer is **A. Spinothalamic Tract**. The spinothalamic tract is a collection of nerve fibers that carry pain and temperature sensation from the body to the brain. Specifically, the lateral spinothalamic tract is responsible for transmitting pain and temperature sensation, while the ventral spinothalamic tract transmits crude touch and pressure sensation. This pathway involves the crossing of sensory information from the contralateral (opposite) side of the body to the spinal cord, where it is relayed to the thalamus in the brain.

**Why Each Wrong Option is Incorrect**
**Option B:** The dorsal column-medial lemniscus pathway is responsible for transmitting fine touch, vibration, and proprioception (position and movement sense) from the body to the brain, but not pain or temperature sensation.

**Option C:** The trigeminal nerve (cranial nerve V) transmits sensory information from the face to the brain, including pain, temperature, touch, and proprioception, but it is not responsible for carrying pain and temperature sensation from the rest of the body.

**Option D:** The posterior (dorsal) roots of the spinal cord transmit sensory information from the body to the spinal cord, but the specific pathway responsible for pain and temperature sensation is the spinothalamic tract, not the posterior roots themselves.

**Clinical Pearl / High-Yield Fact**
The spinothalamic tract is often affected in conditions such as spinal cord injury, where patients may experience loss of pain and temperature sensation on one side of the body.

**Correct Answer:** A. Spinothalamic Tract