Ella (me / nos) compra un recuerdo a mí.
a) me
b) nos

explanation:

it's the camino de santiago pilgrimage trail to santiago de compostela in spain, the location of the alleged tomb of the apostle st james. the track has been walked by pilgrims for over 1,000 years. the one you're referring to is the camino frances, which is around 800kms long, and these days more than 100,000 people walk all or part of it annually. most people still walk for religious, or more often, spiritual reasons, a few just because it's there.  

yes you are correct