Which of the following is true regarding concrete frame construction?

In concrete frame construction, the statement that all parts act in unison is accurate because this method integrates beams, columns, and slabs to work together as a single structural unit. This design maximizes the structural integrity and load distribution throughout the entire frame, enhancing its ability to resist various loads such as gravity, wind, and seismic forces.

In this type of construction, the connections between the beams and columns are crucial, as they enable the entire structure to respond as one cohesive entity rather than as separate components. This interaction is significant for effective load transfer and overall stability, especially in larger buildings where forces can be more variable and complex.

Regarding other options, while beams and columns can be poured independently, they must ultimately function together, which diminishes the viability of that choice. The assertion that concrete frame construction is only suitable for small buildings is also incorrect, as this method is widely used for both small and large structures. Additionally, concrete in structural applications typically requires reinforcement, such as rebar, to improve tensile strength, making that option incorrect as well.