Anchoring safe to Hardwood floor

There was a resent post regarding anchoring safes to concrete, but what about hardwood floors. What works best: Does a carriage bolt with washer and nut work better or a lag screw.

I just ordered a Hollon FB845. It will be in a main floor closet. the safe has one anchor point. I am not exactly sure where it will end up in the basement, but the ceiling is exposed (no drywall or drop ceiling). With enough time and some luck, someone could find the anchor poking through the ceiling. I was thinking of going with a lag screw, and adding a piece of 2x4 (or something similar) access the joist. Any other options?

Thanks!