I voted "Other" because I'm a federal goobermint employee...and our office deals in regulatory enforcement. We get ethics refresher training every year, covering the dos and don'ts of accepting gifts and other situations that might present a conflict of interest...or perception thereof.
Gifts from coworkers are almost never a problem unless there's some kind of manager/subordinate relationship. Then, they must be of nominal value, create no appearance of favoritism or impropriety, etc.