3♣ Obvious to an overbidder. I am not going to defend 2♠ at favourable, when they have a 9-card fit, so I might as well bid immidiately. Even withouth being a passed hand, partner should know I was pre-balancing (MP's). A good partner might even think twice before leading from an unguarded honour in clubs, if she has a good alternative. As there are many warning signs, I wont attemt to get to the best contract, but rather make it likely, that I get to something playable. Thus 3♣ and not double (Of 2♠). (Partner passing that double, would definitely be a nail-biter.) Furthermore, 3♣ is also the most difficult to defend against, as they dont have an uncommitting double available.