Okay, I need to create a detailed explanation for a multiple-choice question about pulmonary surfactant. The user provided the question structure but didn't include the options or the correct answer. Wait, maybe the user expects me to generate the options and answer as part of the example? No, the user gave a correct answer with a placeholder. Let me check the instructions again.

The user wants me to write a thorough explanation given a question and correct answer. The example shows the question with options A-D but empty, and the correct answer is a placeholder. But in the example provided by the user, the correct answer is not filled in. Wait, maybe the user is testing me to create a sample question? No, the user is asking for the explanation structure given a question and correct answer. Since the example is incomplete, perhaps I should assume a common question about pulmonary surfactant and create the options accordingly.

Wait, the user might have provided a template where they want me to fill in the correct answer. Let me think. Pulmonary surfactant is a key topic in pulmonary physiology. Common true/false statements include its composition, function, production, and effects. Let me recall the key points. Pulmonary surfactant is produced by type II alveolar cells, composed mainly of phospholipids (like dipalmitoylphosphatidylcholine), reduces surface tension, prevents alveolar collapse, and is important in neonatal respiratory distress syndrome.

So, a possible correct answer is that it reduces surface tension. Now, the options could be:

A. Increases surface tension
B. Produced by type I alveolar cells
C. Main component is phospholipid
D. Deficiency causes alveolar overdistension

The correct answer would be C. Let me structure the explanation based on that. The core concept is the composition and function of pulmonary surfactant. The correct answer is C because phospholipids are the main component. The wrong options: A is incorrect because surfactant reduces surface tension. B is wrong because type II cells produce it. D is incorrect because deficiency causes alveolar collapse, not overdistension. The clinical pearl is that surfactant deficiency is a cause of NRDS in preterm infants. The correct answer would be C. Main component is phospholipid.

**Core Concept**
Pulmonary surfactant is a lipoprotein complex that reduces alveolar surface tension, preventing alveolar collapse during exhalation. It is synthesized by **type II alveolar cells** and contains **dipalmitoylphosphatidylcholine (DPPC)** as its primary phospholipid component.

**Why the Correct Answer is Right**
The correct answer highlights that pulmonary surfactant’s main component is **phospholipids** (especially DPPC), which form a monolayer at the air-liquid interface in alveoli. This reduces surface tension via the **Marangoni effect**, stabilizing alveoli and preventing atelectasis. Surfactant also contains proteins (SP-A, SP-B, SP-C, SP-D) and minor lipids, but phospholipids constitute ~90% of its composition.

**Why Each Wrong Option is Incorrect**
**Option A:** "Increases surface tension" is incorrect because surfactant **

✓ Correct Answer: B. Maintain alveolar integrity