Answer: c. a spiral ending in a serpent head.
The Oseberg ship is a Viking ship that was found in a large burial mound in Norway. It is one of the finer artifacts to have survived from the Viking Era. The ship is almost entirely made of oak, and the bow, prow and stern of the ship are elaborately decorated with woodcarvings. It has 15 pairs of oar holes, meaning that 30 people could row the ship. One of the decorative features of the ship is a spiral ending in a serpent head, located at the prow of the ship.