Which one of the following lesions of vocal cord is dangerous to life -

Most dangerous lesion of vocal cords is bilateral abductor paralysis (Bilateral RLN palsy). This is because recurrent laryngeal nerve palsy will lead to paralysis of all laryngeal muscles except the cricothyroid muscle (as it is supplied by superior laryngeal nerve). The cricothyroid muscle is an adductor & therefore this will leave both the cords in median or paramedian position thus endangering proper airway, leading to stridor and dyspnea.