**Core Concept**
A linear non-displaced fracture of the mandible is a type of fracture where the bone is broken but the fragments remain in their original position. The treatment of choice for such fractures is a minimally invasive approach that aims to restore the normal occlusion and function of the jaw.

**Why the Correct Answer is Right**
The treatment of choice for a linear non-displaced fracture of the mandible is closed reduction and immobilization. This involves reducing the fracture fragments back into their original position and immobilizing the jaw using an orthodontic elastic band or a mandibular splint. This approach allows for early mobilization of the jaw and minimizes the risk of complications such as malunion or nonunion. The presence of a full complement of teeth also makes it easier to achieve stable fixation and early mobilization.

**Why Each Wrong Option is Incorrect**
* **Option B:** This option may be a distractor for less common or more complex fractures that require surgical intervention, such as a displaced or comminuted fracture.
* **Option C:** This option may be a distractor for fractures that require more extensive treatment, such as a fracture that involves the alveolar process or the mandibular condyle.
* **Option D:** This option may be a distractor for a fracture that requires more aggressive treatment, such as a fracture that is associated with significant soft tissue injury or instability.

**Clinical Pearl / High-Yield Fact**
For linear non-displaced fractures of the mandible, the key to successful treatment is early mobilization of the jaw and stable fixation. This can often be achieved with closed reduction and immobilization, and patients should be advised to follow a soft diet and avoid heavy lifting or bending for several days after treatment.

**Correct Answer: A. Closed reduction and immobilization.**