It haven't taken Spanish since middle school, but I don't think we used "accent" the way it's used in this sentence. The answer sounded very odd to me at first. If you're talking about the diacritic itself, we'd say, "Where is the accent placed" or "Which letter/syllable has the accent/is accented". If you're talking about how it sounds, you would say, "Where is the stress/emphasis placed".
Fair enough. As a native American English speaker, I don't hear or use "accent" to mean emphasis within a word - maybe in poetry? I think @Luke_5.1991 was referring to the diacritic symbol e.g. é used in Spanish etc. "Where is the accent (symbol)? That interpretation is the only way the answer makes sense to me, and even so it's unnatural to my ears.
I'm not a native American English speaker, but for example http://www.merriam-webster.com/dictionary/accent says "greater stress or force given to a syllable of a word in speech" and a mark (such as ˈ or ˌ) used to show the part of a word that should be given greater stress when it is spoken
Chambers dictionary, defines "accent" (amongst other things) as "stress on a syllable, word, or note" and "a mark used to direct this stress".
That said, I'm a native (British) English speaker (who studied English language to A-level) and I've never heard "accent" used in this way! Like others have said, we use "stress/emphasis" instead.