This is not an ideal question since in practice the answer depends on other GMs' valuations of Arencibia and d'Arnaud, but whatever. State what you think their relative market value is if you want.

Neither.  With d'Arnaud's knee injury, I plan on moving him to left-field.  I hate "aggressively shopping" anyone.  That doesn't mean that if I am interested in a player and somebody enquires about Arencibia and d'Arnaud in return, I would be open to it.

Arencibia is a slightly below-average catcher.  To a team looking for power, he might have more value than that, and that is what I would hope to capitalize on.  The ideal would be acquire a left-handed hitting left-fielder with lead-off skills, or (of course) a starting pitcher. d'Arnaud presumably has significantly more value because of both service time and ability differences. 

"Aggressively" shopping?  Neither.  Not to say one of them couldn't be traded this offseason....

I shop d'Arnaud. I have a lot more confidence in the hitters on this team than the pitching.  We need reliable starters.  I think d'Arnaud has more value and will fetch more. The only caveat is if JP is really as miserable at calling a game as has been suggested then I take it all back and shop JP and see what I can get.

No one is untouchable, but I would be disinclined to trade d'Arnaud unless the Jays are getting back someone like Profar (not that the latter makes the most sense positionally, but that's the calibre of player I would want in return). And trading for young SPs is risky - imagine if the Jays had traded d'Arnaud for Pineda last off-season. That might have been a historically bad trade.

"Aggressively shopping" them would reduce their trade value, because other GMs would quickly assume that something is wrong with whomever is being shopped. Anthopoulos will attempt to convey to other GMs that he covets both of them, that they are both future superstars, but that he MIGHT reluctantly give up one of them if the price is high enough.

Still, it's a great poll question, since I just can't see AA solving his roster problems on the free agent market. Catcher and shortstop are the two areas of surplus, and both are seller's markets, since there isn't a huge number of good catchers and shortstops available on the market.

We should have a similar poll on shortstop: should AA trade Escobar or Hechavarria or Aviles?

The answer to both the SS and C questions, I suspect, is that any or all of them could be available, depending on the return. The Jays need a top pitcher, and AA would be foolish to have any untouchables (except Bautista) if he has a chance to get a top-of-the-rotation starter.

Everything China fan just said, minus the except Bautista part.

I think Bautista has to be "almost" untouchable. I would trade him for Weaver or Verlander or maybe a few others. Sure wouldn't be shopping him though.

I don't aggressively shop. Smacks of desperation. Let the deal come to you. Or bait and switch.

Neither - i don't see "aggressively shopping" anyone as ever being a good strategy. it certainly hasn't worked for the dbacks with j/upton so far, anyway.
more specifically, doing so with a guy whose had as much injury trouble as d'Arnaud is probably going to raise red flags for anyone looking at him. Similarly, pushing one over the other on potential trade partners is likely to only highlight the deficiencies in the minds of the buyer(s).

As this Team is aggressively pursuing Front-line Starting Pitching, only Bautista, Encarnacion, Lawrie, Morrow, Romero and Santos are untouchable.  To aggressively promote anyone is unwise, reluctance works better.