Deer mice normally do not travel far from their nests, and deer mice that are moved more than half a kilometer from their nests generally never find their way back. Yet in one case, when researchers camped near a deer mouse nest and observed a young deer mouse for several weeks before moving it to an area over two kilometers away, the deer mouse found its way back to its nest near their camp in less than two days. Which one of the following, if true, most helps to explain how the deer mouse might have found its way back to its nest? ['The area to which the deer mouse was moved was dryer and more rocky than the area in which its nest was located.', 'Animals that prey on deer mice were common in the area to which the deer mouse was moved.', 'The researchers had moved the deer mouse in a small dark box, keeping the mouse calm before it was released.', 'The researchers released the deer mouse in a flat area across which their campfire smoke drifted.']