**Core Concept**
The question is testing the student's knowledge of the potency of various corticosteroids in terms of their anti-inflammatory effects. Corticosteroids are a class of steroid hormones that are produced by the adrenal cortex and play a crucial role in regulating inflammation, immune response, and metabolism.

**Why the Correct Answer is Right**
The correct answer is Dexamethasone, which is a synthetic corticosteroid that is known for its high potency and long duration of action. Dexamethasone exerts its anti-inflammatory effects by binding to glucocorticoid receptors in the cytoplasm, which then translocate to the nucleus and regulate the expression of various genes involved in inflammation. This includes the inhibition of pro-inflammatory cytokines, such as TNF-alpha and IL-1 beta, and the induction of anti-inflammatory cytokines, such as IL-10.

**Why Each Wrong Option is Incorrect**
* **Option A:** Prednisolone is a corticosteroid that is commonly used in the treatment of various inflammatory conditions, but it is not as potent as Dexamethasone.
* **Option B:** Hydrocortisone is a corticosteroid that is produced by the adrenal cortex and is involved in the regulation of inflammation, but it is not as potent as Dexamethasone.
* **Option C:** Methylprednisolone is a corticosteroid that is similar to Dexamethasone in terms of its potency and duration of action, but it is not as potent as Dexamethasone.

**Clinical Pearl / High-Yield Fact**
It's worth noting that the potency of corticosteroids can vary depending on the specific condition being treated, and the choice of corticosteroid should be based on the severity of the condition, the patient's response to treatment, and potential side effects.

**Correct Answer:** D. Dexamethasone