<prompt> 17 year old boy presented to the outpatient with giddiness and hypeension. X-ray chast revealed anterior notching of 4th to the 8th ribs. What is the likely diagnosis?Coarctation of aoaNeurofibromatosisCollagen vascular diseasePneumonia  <response>: The findings here are typical of Coarctation of aoa anterior notching. Neurofibromatosis causes posterior notching of ribs. 