This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuroanatomy, Subject name: Anatomy
Which of the following fibers reach Purkinje cells directly? 
Select and explain. 
A. Vestibular nuclei, B. Inferior olivary nucleus, C. Raphe nucleus, D. Locus coeruleus
B: Inferior olivary nucleus
Answer: B: Inferior olivary nucleus 
Explanation: Ans. B. Inferior olivary nucleus* Only fibers reaching Purkinje cells directly in the outer molecular layer are climbing fibers originating from inferior olivary nucleus of medulla oblongata constituting olivocerebellar and para olivocerebellar tract.* Rest all other tracts are called Mossy fibers.