**Core Concept**
Bell's palsy is an idiopathic peripheral seventh cranial nerve (facial nerve) palsy, characterized by sudden onset of unilateral facial weakness or paralysis. The prognosis of Bell's palsy is generally favorable, with the majority of patients recovering completely.

**Why the Correct Answer is Right**
The correct answer is not provided, however, a favorable prognostic indicator in Bell's palsy is the presence of early recovery of facial function, particularly within the first two weeks.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided, however, an unfavorable prognostic indicator would be the presence of complete paralysis, which may indicate a poorer outcome.
**Option B:** Similarly, this option is not provided, but advanced age or the presence of underlying medical conditions may also indicate a poorer prognosis.
**Option C:** Again, this option is not provided, but a lack of improvement within the first two weeks may indicate a poorer outcome.
**Option D:** This option is also not provided, however, the presence of severe pain or a history of previous episodes may also indicate a poorer prognosis.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that the majority of patients with Bell's palsy will recover completely, and early treatment with corticosteroids can improve outcomes.

**Correct Answer:** Correct Answer: D. Recovery within 2 weeks.