Final answer:
The upper edges of the sides of a boat are known as gunwales or gunnels and are part of the hull.
Step-by-step explanation:
The correct answer is (c) Hull. In the context of boats, the word 'hull' refers to the main body or frame of the boat, including the sides and bottom. The upper edges of the sides of a boat are part of the hull and are known as gunwales or gunnels, pronounced 'gŭn-əlz.' The gunwales provide stability and structural support to the boat.