**Core Concept**
Ketone bodies, including acetoacetate, beta-hydroxybutyrate, and acetone, are water-soluble molecules produced by the liver as an alternative energy source during periods of low glucose availability. They are utilized by various tissues as an energy substitute.

**Why the Correct Answer is Right**
Red Blood Cells (RBCs) lack mitochondria, the organelles necessary for the oxidation of ketone bodies to produce energy. As a result, RBCs cannot utilize ketone bodies for energy production. In contrast, other tissues like skeletal and cardiac muscles, as well as the liver, can metabolize ketone bodies for energy.

**Why Each Wrong Option is Incorrect**
**Option A:** Skeletal muscles can utilize ketone bodies as an energy source, especially during prolonged exercise when glucose availability is limited.
**Option B:** Cardiac muscles, like other muscles, can metabolize ketone bodies to produce energy, particularly during states of ketosis.
**Option C:** The liver produces ketone bodies but also utilizes them as energy when glucose availability is low. This is a unique characteristic of the liver, making it a key player in ketosis.

**Clinical Pearl / High-Yield Fact**
Ketosis, a metabolic state characterized by elevated levels of ketone bodies, is typically seen in fasting, starvation, or low-carbohydrate diets. It is also a hallmark of diabetic ketoacidosis (DKA), a serious complication of diabetes mellitus.

✓ Correct Answer: D. RBC