I cut it with a knife.
Which is the proper rewrite?
a) I used a knife to cut it.
b) I used a knife to cut it with.
Should with be attached to the end of the sentence?
I vote for (a), but another person votes for (b). I don't think I'm wrong, but I'm not a native speaker of English, so I need a native speaker or two to comment on this. Thank you.