**Core Concept**
Diabetic ketoacidosis (DKA) is a serious metabolic complication of diabetes characterized by hyperglycemia, metabolic acidosis, and the production of ketone bodies. It occurs when the body produces high levels of glucose and ketones due to a lack of insulin, leading to an imbalance in electrolytes and fluid status.

**Why the Correct Answer is Right**
DKA typically develops in patients with type 1 diabetes, although it can also occur in patients with type 2 diabetes, especially during periods of stress or illness. The condition is caused by a deficiency of insulin, which leads to an increase in glucagon levels, resulting in the breakdown of fat for energy and the production of ketone bodies. The metabolic acidosis in DKA is caused by the accumulation of ketones, which are acidic in nature.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because DKA is indeed characterized by hyperglycemia, which is a key feature of the condition. Elevated blood glucose levels are a result of the body's inability to use insulin effectively.

**Option B:** This option is incorrect because metabolic acidosis is a hallmark of DKA, caused by the accumulation of acidic ketone bodies in the body. The condition can lead to severe complications if left untreated.

**Option C:** This option is incorrect because DKA is a known complication of diabetes, particularly in patients with type 1 diabetes. The condition can also occur in patients with type 2 diabetes, especially during periods of stress or illness.

**Clinical Pearl / High-Yield Fact**
DKA is a medical emergency that requires prompt treatment to prevent complications such as cerebral edema, cardiac arrest, and even death. Early recognition and treatment of DKA can significantly improve outcomes for patients with this condition.

**Correct Answer: D.**