The correct answer is D. All the above.
A king post truss is a type of roof truss that uses a vertical post, called a king post, to support the weight of the roof. The principal rafters are the main beams that support the roof, and the tie beams are the horizontal beams that connect the principal rafters. The joint between the principal rafter and the tie beam is called a bridle joint, and the joint between the principal rafter and the king post is called a mortise and tenon joint. The joint between the strut and the king post is also generally a mortise and tenon joint.
A bridle joint is a type of joint that is used to connect two pieces of wood at a right angle. The joint is made by cutting a groove in one piece of wood and a tongue in the other piece of wood. The groove and tongue are then fitted together and secured with glue and nails or screws.
A mortise and tenon joint is a type of joint that is used to connect two pieces of wood at any angle. The joint is made by cutting a rectangular hole in one piece of wood (the mortise) and a corresponding rectangular piece of wood (the tenon) in the other piece of wood. The tenon is then fitted into the mortise and secured with glue and nails or screws.
A strut is a structural member that is used to support a load by resisting compression. In a king post truss, the struts are located between the principal rafters and the king post. The struts help to transfer the weight of the roof from the principal rafters to the king post, which then transfers the weight to the foundation.