Which of the following muscle relaxant can cause pain on IV injection Site

C i.e. Rocuronium - Rocuronium is desacetoxy analog of vecuronium with a low potency (1/6 - 1/8 of vecuronium) and so rapid onset of action (because potency and speed of onset are inversely related). It is the fastest (most rapid) acting nondepolarizing muscle relaxantQ (75 sec), which is slightly slower than depolarizing muscle relaxant succinylcholine only. * Rocuronium injection can cause pain on injection siteQ, which may be decreased by alkalinizing the solution. Other painful injections include etomidate, propofol, methohexital and thiopentalQ.