Which nucleus gives off parasympathetic preganglionic fibers to enter facial nerve in brainstem? A: inferior salivatory nucleus B: nucleus ambiguus C: superior salivatory nucleus D: dorsal nucleus of vagus nerve

Which nucleus gives off parasympathetic preganglionic fibers to enter facial nerve in brainstem?() A: inferior salivatory nucleus B: nucleus ambiguus C: superior salivatory nucleus D: dorsal nucleus of vagus nerve E: accessory nucleus of oculomotor nerve