**Core Concept**
The medulla oblongata, a part of the brainstem, is supplied by multiple arteries that arise from the vertebral and basilar arteries. These arteries are responsible for providing oxygenated blood to the medulla, which is crucial for its function and survival.

**Why the Correct Answer is Right**
The medulla is primarily supplied by the vertebral and basilar arteries, which give off branches such as the anterior spinal artery, the posterior inferior cerebellar arteries, and the superior and inferior cerebellar arteries. However, the middle cerebral artery does not directly supply the medulla. Instead, it supplies the lateral surface of the cerebral hemisphere, including the frontal, parietal, and temporal lobes. The middle cerebral artery's territory does not extend to the brainstem or the medulla.

**Why Each Wrong Option is Incorrect**
**Option A:** Not provided, skipping this option.
**Option B:** This option is not provided, skipping this option.
**Option C:** This option is not provided, skipping this option.
**Option D:** This option is not provided, skipping this option.

**Clinical Pearl / High-Yield Fact**
It's essential to remember the vascular territories of the brain, including the brainstem, to understand the clinical consequences of strokes and vascular malformations in this region. The vertebral and basilar arteries are particularly important to identify in imaging studies to diagnose and manage conditions affecting the brainstem.

**Correct Answer: A.**