The correct answer is D) parallel to the pier from ahead. When docking a vessel, the most favorable wind and current conditions are when they are parallel to the pier from ahead. This allows the vessel to approach the pier straight on, with the wind and current pushing the vessel towards the pier. This makes the docking maneuver easier to control and execute safely. The other options are incorrect because: A) crossing winds and currents in opposite directions can make the approach more difficult to control, B) being set on the pier by the wind and current could cause the vessel to impact the pier with too much force, and C) crossing winds and currents in the same direction could push the vessel away from the pier, making the approach more challenging.