If there's any doubt then there's no doubt - ASK!!
I always assume that I'm responsible for my own terrain seperation, consult the relevant topo and make sure I don't hit the cumulus granitus. If you are not happy then clarify the clearance, if it's somewhere unfamiliar then study the terrain on the topo, draw out the approach/sid if you have to. That has saved my bacon a fair few times.
The one that nearly got me was about 10 years ago, cleared to descend to the next sector safe alt on the radar Vector chart, IMC, then 'Avoiding action, turn right 090 degrees - pop up traffic 12-O'clock at 4 miles' Unfortunately, that pointed us straight at a 3700ft peak when we were cleared to 2700ft in the adjacent sector. Fortunately, we noticed!
Fly safe, ask that stupid question.