**Core Concept**
Long-acting glucocorticoids are synthetic corticosteroids with a longer duration of action, typically used for chronic inflammatory conditions or as a maintenance therapy. These medications have a slower onset of action but a more prolonged effect, allowing for less frequent dosing.

**Why the Correct Answer is Right**
The mechanism of long-acting glucocorticoids involves their resistance to metabolic degradation, which prolongs their action. Cortisol, the natural glucocorticoid, is rapidly metabolized by the enzyme 11-beta hydroxysteroid dehydrogenase (11β-HSD2) in the kidneys. Long-acting glucocorticoids, such as dexamethasone, are resistant to this enzyme and therefore have a longer duration of action.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specify a long-acting glucocorticoid. Short-acting glucocorticoids, such as hydrocortisone, have a shorter duration of action.

**Option B:** This option is incorrect as it does not mention a specific glucocorticoid. Many glucocorticoids have varying durations of action, and this option does not provide enough information to determine its classification.

**Option C:** This option is incorrect as it does not specify a long-acting glucocorticoid. Intermediate-acting glucocorticoids, such as prednisolone, have a duration of action that falls between short-acting and long-acting glucocorticoids.

**Clinical Pearl / High-Yield Fact**
It's essential to note that long-acting glucocorticoids can cause adrenal suppression, requiring careful monitoring and gradual tapering of the medication when discontinuing treatment.

**Correct Answer:** D. Dexamethasone is a long-acting glucocorticoid with a duration of action that typically lasts for 48-72 hours.