Shouldn't this be "Der weißer Wolf", because 'white wolf' is in the nominative case, and wolf is masculine? The hint drop-down indicates that the white they provide is feminine.
Never mind, I found out why: I need to use a weak inflection (with article) because "Der" is present preceding the adjective. So the correct answer is "weiße."
yes. Der weiße Wolf /// Ein weißer Wolf
http://en.wikipedia.org/wiki/German_declension#Weak_inflection.5B6.5D.5B7.5D This will help you understand