<prompt> A recognised cause of stridor in newbornCystic hygromaA Vascular ringLaryngomalaciaAll are true  <response>: StridorStridor refers to the physical finding of excessively noisy breathing and is generally due to airway obstruction.Causes of Stridor in a child.InfectionsCroup laryngotracheobronchitisEpiglottitisBacterial tracheitisRetropharyngeal abscessCongenitalLaryngomalaciaVocal cord palsySubglottic stenosisVascular ringSaccular cystNeoplasmsSubglottic hemangiomaLaryngeal papillomasCystic hygroma, when it occurs in larynx then it can cause respiratory tract obstruction - Nelson 18thep. 1773 