The correct answer is D) If the vessel is sailing with the wind aft. In a wing and wing configuration, the sails are set with one sail on each side of the vessel, allowing the vessel to sail directly before the wind. This configuration is most effective when the vessel is running or reaching, with the wind blowing from behind the vessel. The other options are incorrect because: A) Close-hauled sailing requires the sails to be trimmed closer to the centerline of the vessel; B) Wearing refers to turning the vessel away from the wind, which would not necessitate a wing and wing configuration; and C) Tacking into a headwind requires the sails to be positioned differently to allow the vessel to zigzag into the wind.