**Core Concept**
Type 1 Brittle asthma is a severe and unstable form of asthma characterized by sudden and unpredictable attacks, often with normal or near-normal lung function between episodes. The pathophysiology involves a complex interplay between airway inflammation, airway hyperresponsiveness, and dysregulated airway smooth muscle function.

**Why the Correct Answer is Right**
The drug of choice for Type 1 Brittle asthma is typically a high-dose inhaled corticosteroid, often in combination with a long-acting beta-2 agonist (LABA). This combination helps to control airway inflammation and prevent severe exacerbations. In addition, the use of a LABA, such as salmeterol or formoterol, can help to improve lung function and reduce symptoms.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because oral corticosteroids are typically reserved for short-term use in severe exacerbations, and chronic use is associated with significant side effects.
**Option B:** This option is incorrect because theophylline has a narrow therapeutic index and can cause significant side effects, making it a less desirable choice for long-term management of brittle asthma.
**Option C:** This option is incorrect because montelukast is a leukotriene receptor antagonist that may not be effective in controlling the severe inflammation and airway hyperresponsiveness seen in Type 1 Brittle asthma.

**Clinical Pearl / High-Yield Fact**
In brittle asthma, the goal of treatment is to prevent severe exacerbations and improve quality of life, rather than simply controlling symptoms. This often requires a combination of high-dose inhaled corticosteroids and LABAs, as well as careful management of comorbidities and other medications.

**Correct Answer: C. Montelukast.