You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.

Category: ART 
Clue: Medieval artists gave triangular ones to the trinity, round to the angels & rectangular to living holy people
halos

Category: LITERARY E-MAIL ADDRESSES 
Clue: ageless-wonder@wilde-pictures.com
dorian gray

Category: A CLOSE LOOK AT ART 
Clue: In his "Night Watch", hierarchy is shown by the shadow of the militia captain's hand on an underling's coat

rembrandt