I would choose C. I could feed the bunny until it is so fat that I could make a boat out of it and sail back to land. In the meantime, I wouldn't find helping myself to some delicious greenery as well. Assuming delicious greenery includes artificially coloured green meat.
Notice he didn't ask the question of non-atheists? Because he knows that the rest of us would fire something at the bunny and enjoy a good meal.
Well, the smart ones would kind of adopt c), but then find another bunny to make baby bunnies... which would make more baby bunnies and then you'd have an endless supply of bunnies to eat. I would fire the cannon for entertainment.
And the REALLY smart ones, (I don't fall in this category, I stop at having a supply of food.) would breed even more bunnies, find a way of receiving payment and use the cannon to deliver the product (bunnies).