Which framing members establish a rough floor opening?

The framing members that establish a rough floor opening are trimmers, headers, and tail joists. Trimmers, also known as king studs or jack studs, are installed alongside openings to support the header, which is a horizontal framing member that spans the opening and transfers loads to the surrounding structure. Tail joists, often connected to headers, extend from the openings and help support the floor system.

Understanding this relationship is crucial for proper framing techniques. When creating an opening for doors, windows, or other architectural features, these members are essential to ensure that the opening maintains structural integrity while supporting the loads above. This specific arrangement allows floor openings to be framed correctly, ensuring stability and safety in the building.

The other options involve different components that serve other purposes in residential construction. For instance, rafters, beams, and posts are primarily associated with roof framing, studs, plates, and blocks are used in wall construction, while joists, sheathing, and nails pertain to floor systems but do not specifically relate to creating a rough opening. Thus, option C accurately describes the correct framing members associated with establishing a rough floor opening in construction.