adwords question redirect vs keyword url

Hey everyone,
simple question.. but I've no idea how it turns out which ever way I decide to try..

what is better?

a) having a adwords display url domain.com, with a destination domain a url forward redirecting traffic back to the domain.com .. then changing that redirect URL to something different (switching the redirect on my end)

or

b) having a adwords ad with a proper display and destination url, then forwarding from a keyword within adwords? (theres an option to add a different url for a keyword)

both instances the user gets redirected to something different. What are the chances either one of these methods will get busted faster than the other? or would method b) be an all around better method?

Any ideas?

Never tried option A but option B is kind of the traditional trick. It used to last forever a couple of years ago but it gets caught on to pretty quick these days.