Answer:
I think the answer is number 4 or 1, I think that it's most likely the first one because "p.r.i.c.k.l.e.s their spine " is not exactly a metaphor, and "anticipation is a grip on their hearts" seems to be a bit more metaphoric than the others.
To save you from my paragraph of rambling, I believe the answer is the first one.
hope this helps! :)
