**Core Concept**
Metabolic alkalosis is a condition characterized by an increase in blood pH due to an increase in bicarbonate levels. Chloride-responsive metabolic alkalosis typically involves a primary decrease in chloride levels, leading to a compensatory increase in bicarbonate reabsorption in the kidneys. The kidneys respond to chloride depletion by increasing the reabsorption of bicarbonate, thereby correcting the alkalosis.

**Why the Correct Answer is Right**
Chloride-responsive metabolic alkalosis is typically caused by conditions such as pyloric stenosis, vomiting, or nasogastric suction, which lead to a loss of gastric acid and chloride ions. The kidneys respond to this chloride depletion by increasing bicarbonate reabsorption, leading to an increase in blood pH. In contrast, non-chloride responsive metabolic alkalosis is caused by conditions such as primary hyperaldosteronism or mineralocorticoid excess, which lead to an increase in sodium reabsorption and potassium excretion, but not a decrease in chloride levels.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because conditions such as pyloric stenosis, which lead to a loss of gastric acid and chloride ions, typically cause chloride-responsive metabolic alkalosis.

**Option B:** This option is incorrect because conditions such as primary hyperaldosteronism, which lead to an increase in sodium reabsorption and potassium excretion, typically cause non-chloride responsive metabolic alkalosis.

**Option D:** This option is incorrect because conditions such as nasogastric suction, which lead to a loss of gastric acid and chloride ions, typically cause chloride-responsive metabolic alkalosis.

**Clinical Pearl / High-Yield Fact**
When diagnosing metabolic alkalosis, it is essential to differentiate between chloride-responsive and non-chloride responsive causes. This can be done by assessing the patient's chloride levels and response to chloride supplementation.

**Correct Answer: B. Primary hyperaldosteronism**