**Core Concept**
Laryngomalacia is a congenital condition characterized by soft and pliable cartilaginous structures of the larynx, leading to partial airway obstruction during inspiration. This condition is the most common cause of stridor in infants.

**Why the Correct Answer is Right**
Laryngomalacia typically presents in the first few weeks of life, with symptoms such as stridor, cyanosis, and feeding difficulties. The condition is often associated with an overhanging epiglottis or a thin and floppy aryepiglottic fold. The partial airway obstruction can lead to increased work of breathing, respiratory distress, and potential failure to thrive.

**Why Each Wrong Option is Incorrect**
**Option A:** Laryngomalacia is often associated with an overhanging epiglottis or a thin and floppy aryepiglottic fold, which can cause partial airway obstruction. This statement is true and not the correct answer.
**Option B:** Stridor is a common presenting symptom of laryngomalacia, often heard during inspiration. This statement is true and not the correct answer.
**Option C:** Laryngomalacia can be associated with other congenital anomalies, such as tracheoesophageal fistula or esophageal atresia. This statement is true and not the correct answer.

**Clinical Pearl / High-Yield Fact**
A key clinical feature of laryngomalacia is the improvement of symptoms with prone positioning, as this can help reduce the degree of airway obstruction.

**Correct Answer: D**