Some small fixes: Your quiz doesn't accept Velazquez as an answer, but it does accept Velazques. Rodin also created a work called "The Kiss," which creates a conflict with the Klimt answer that could be avoided by choosing another Klimt artwork. And one of Raphael's works is called "The School of Athens," which is a lot closer to the subject of the Athenaeum (not Atheneaum) than Stuart's famous portrait of Washington. I might feel more accepting of that answer if I had known that the portrait was also given that title, but it seems needlessly obscure, not to mention confusing.
Not sure what's up with Velazquez; it worked for me. And I think I'll stick with The Kiss for Klimt, as it's probably the most famous of his works (totally subjective, but whatever). And yes, the Athenaeum is confusing--I didn't even know it was called that until I looked it up! --Fixed. Thanks!