The keel and the planks of a boat collectively form what part?

The correct choice is the hull, which refers to the entire body or structure of a boat below the deck. The keel is the main structural element that runs along the bottom of the boat from the bow to the stern, providing stability and strength. The planks, whether they are part of a wooden boat's construction or represent the material making up the hull, contribute to the overall shape and integrity of the boat.

The hull is crucial for maintaining buoyancy and protecting the internal components of the vessel from water. Together, the keel and the planks create a waterproof structure that allows the boat to float and navigate on water. Understanding the hull's role is essential in boating, as it influences the vessel's performance, speed, and handling characteristics.

The other options, while related to a boat’s structure, do not encompass both the keel and the planks. The deck refers to the top surface of the boat where activities take place, the transom is the flat surface at the rear of the hull, and the framework typically refers to the internal structure supporting the hull but does not collectively identify it with the keel and planks.