Romans were HUGE traders, this is mostly because they didn't have many natural resources. ( Well they did, but not the ones that you seem to be looking for in this question. ;) )
A is a one of the options. Rome didn't have spice or silk, and they acquired this from the east, countries like China and India are examples.
So Silk was a major product for the romans, so B is an answer as well.
C is not an accurate option because Rome did not have or grow the material needed for silk.
D im not sure about, I recommend going back on your notes or lesson an looking this one up.
Hope I helped. :) Thanks for using Brainly! :D