<prompt> Which of the following muscle relaxants causes maximal pain on injectionSuccinyl cholineVecuroniumRocuroniumCistracurium  <response>: The major disadvantage of rocuronium is the pain associated with its injection, the cause of which is not clear. With a subparalysing dose, 50-100 of patients repo discomfo.Even after induction of anaesthesia with propofol or thiopental, rocuronium causes hand or limb withdrawal in 85 of patients, suggesting the presence of intense nociception, even during anaesthesia 