**Core Concept**
Bell's palsy is a form of idiopathic facial paralysis characterized by the sudden onset of unilateral lower motor neuron weakness or paralysis of the facial nerve. The underlying pathophysiology is thought to be related to inflammation and demyelination of the facial nerve within the facial canal.

**Why the Correct Answer is Right**
The most effective treatment for Bell's palsy is corticosteroids, which have been shown to reduce the incidence of residual facial weakness and improve symptoms when initiated within the first 72 hours of onset. Corticosteroids, such as prednisolone, work by reducing inflammation and preventing further damage to the facial nerve. The use of corticosteroids in Bell's palsy is supported by evidence from numerous clinical trials, including the idiopathic Bell's palsy study group.

**Why Each Wrong Option is Incorrect**
**Option A:** Antiviral medications, such as acyclovir, are sometimes used in the treatment of Bell's palsy, but their effectiveness is still a topic of debate and are not the primary treatment of choice.
**Option B:** Physical therapy and facial exercises can help improve facial function and reduce the risk of long-term complications, but they are not the primary treatment for acute Bell's palsy.
**Option C:** Surgery, such as decompression of the facial nerve, is sometimes considered in cases of Bell's palsy, but it is not the first line of treatment and is typically reserved for patients with severe or persistent symptoms.

**Clinical Pearl / High-Yield Fact**
Corticosteroids should be initiated within 72 hours of onset of symptoms in patients with Bell's palsy to maximize the effectiveness of treatment.

**Correct Answer:** C. Physical therapy and facial exercises can help improve facial function and reduce the risk of long-term complications, but they are not the primary treatment for acute Bell's palsy.