3. See the picture below, which numbers show the followings: optic never,optic chiasm, and olfactory bulbVIIIVIIXIIIIIIItrVIрIVIX X X1

II optic nerve
I Olfatory nerve
there are 12 craneal nerves and the optic nerves is the second (2)
the optic chiasm is part of the Optic nerve is where the nerves cross
and the olfatory bulb is part of the olfatory nerve